DD's trip to Europe and flying ?s

The only thing that helps my ears is a full yawn. Just opening my mouth wide doesn't do it so I have to look out for someone else yawning so it triggers me to yawn too 
Yes, she can take snacks. She will be able to buy water and other drinks on the flight if she doesn't get one after her hand luggage has been through the check.

I like to have a variety of little preoccupations, say, crosswords, a book, a magazine etc.

If she likes the dark for sleeping an eye mask can be helpful. I like neck pillows 

Spare pair of socks. My feet often feel chilly once my shoes are off.

Toothpaste (small tube) and face wipes for freshening up on arrival.

Since she has never flown--get the wrist bands that prevent motion sickness. They do work, at least for me. I get motion sickness very easily and they have saved me on flights. As mentioned, you can take snacks and water. A flight to Europe is nice. At the end of the flight the airline brings a warm towel to help you freshen up for the landing (or they still did this last time I had an international flight).

Reading material is essential!

Earplanes for the ear pressure.

Remind me which country/countries she's going to..... which souvenirs to buy will depend where she's going obviously.

I would say to save money, have her bring an EMPTY water bottle through security & have one of the restaurants on the other side fill it up with water (or have her find a water fountain to fill it up). Bottled water in the airports are so expensive, as is food.

For food, I like to bring my own trail mix, I buy a bag of roasted, unsalted almonds, a bag of cranberries & a bag of M&M's and mix them all together. I put it in a gallon ziplock bag & I always have that on hand, I don't eat the entire bag during the flight over, but I like to have some snacks in my travel purse in case I get the munchies sightseeing or in my hotel room when I wake up at 3 in the morning & can't sleep.

DRAMAMINE is the BEST!! I am tall (6'2") and it's very hard for me to sleep on planes. I take a Dramamine and it makes me groggy enough to zonk out for awhile. In a pinch, Benedryl works too.

Earplanes earplugs are great for ears too.

Tell her to get up and walk around/stretch on the plane every couple of hours or so to get the blood circulating in her legs. She would not want deep vein thrombosis while on a trip of a lifetime!

All international flights serve meals, so if she's not too picky of an eater, she will for sure get 2 meals on the plane depending on where she's flying from (for example, from San Franciso to anywhere in Europe, we get dinner & breakfast plus snacks on the plane). I do supplement with my trail mix if I get snacky during the flight.

For things to do, if she has a kindle or some type of e-reader, she should load it up with books she wants to read before getting onboard. Same with an iPad or similar device, she should download any movies she may want to watch while in the US before she gets on the plane. If they have Wifi on the plane it's usually very expensive and VERY VERY slow, so watching movies/TV shows is nearly impossible. Also, most overseas flights have movies onboard. Check the flight number/type of plane on the airline's website and it should tell you what type on "onboard entertainment" they have. For example, I watched 5 movies San Francisco to Munich and they had the screen in the seat back in front of me, so I could choose what I wanted to watch.

Totally not necessary, but I was so glad I brought this: you know those little single serving packets of Jif peanut butter? I brought a box of those (I checked them because they are considered a liquid) and when I got to whatever country I was going to, I would find bread (baguette, buns, etc) and have a peanut butter sandwich if I was feeling homesick or just wanted something familiar. It really helped during the month I was in Italy during their worst snowstorm in 20 years, we couldn't leave our hotel because it was so bitterly cold and none of the shops were open (we bought bread the first day we got in) and the peanut butter saved us from starving. LOL

Sorry for the book but I hope it helps!

As for souvenirs, some of my favorites I've purchased during my travels:

Christmas ornaments & magnets from all the places we visited
A couple of scarves in France
A purse, wallet, knit cap & gloves in Italy
an amber necklace & earrings from Denmark
a silver necklace from the V&A in London
Lace in Germany

I've purchased other silly things in the past (pens, notepads, etc) that just end up in the garbage. I like buying something I will use regularly now instead of cheap tchotkes.

Wear comfortable shoes that are easy on/off.

Late in life I have discovered the very best way to clear your ears. It can be slightly painful for a moment when you're doing it, but it works like a charm: pinch your nose closed with your fingers as if you were going to jump in a pool, tight enough that you can't breathe at all through your nose. Then try to force air out your nose, as if you were blowing your nose. Somehow, I don't know how, this pops the pressure in your ears. Whatever, it works great.

For souvenirs, I always like to collect tea towels ... linen dish towels. Most of the places I go have them. I use them and also give them as gifts. Museum shops have the best ones.

I wasn't allowed to take an empty bottle through last time I flew. I had to throw it and buy a bottle of water after I went through passport control.

There are lots of tacky "souvenirs" available in London (if that's one of her destinations) most of them made in China and Taiwan- so I would advice her not to waste her money! Personally I don't think you can beat photos and I although I love Christmas ornaments from other countries ( my daughter bought me back the most adorable little blue patterned pottery Santa from Holland in November ) not all places sell them out of season- I couldn't name anywhere in London to find one.

My favourite souvenirs are books of the places that I went to. Ex: when I went to Tower of London I bought the Official Guide. Often you aren't allowed to take photos inside so the guide gives me those photos. The guidebooks are usually thin (so they don't take up much room) but they have great photos and the history of the place.

I take photos everywhere and then make a photobook of the trip when I return.

I also like t-shirts from areas I have been. Every time I wear them I remember my trip.

All these souvenirs do not take up much room in your luggage.

Try gum, or lollipops for the ear pressure. Or sometimes I will take gulps of water and swallow to get my ears to pop. Also, puff up my cheeks and plug my nose. That always helps to relieve the ear pressure. Half a tablet of dramimine will help. It will keep the queasy feeling away, but not totally knock her out.

We always pack some snacks. I will throw in small packages of crackers, cookies, etc. And we carry on a water bottle. If it's a redeye flight, buy something to cover the eyes. Either an eye mask or even a scarf will work. Neck pillows have always been a waste for us. It takes up too much room.

My favorite souvenirs that dh brought home form London, were shortbread cookies and candies that came in little decorative tins, pens, coasters, key chains, a scarf. Just little things.

To ensure her comfort I recommend booking her into a lie-flat seat. It's the only way to travel!

The same method she uses to clear for diving use for ascending and descending in plane.  I detest chewing gum we always have sucky candies on hand.  

Buy water after clearing security. 

As soon as she can after meal service, tell her to get up and use the restroom. Once they come around to pick up trays, everyone and their mother will get in line for the restroom. Try to beat that crowd.

Oh and I love traveling with a hoodie. You can put that hoodie up to shield your face a bit if you are trying to sleep.