Pains now, but long term will be great!

Today I had an employee quit. Right at the absolute worst time. She didn't give a two week notice. It will be a PITA to find someone and train them in this busy time. But long term will be great! She is such a negative Nancy. She does just enough where I can't write her up. She complains about everything. Just the day before I was talking to my admin about the situation. We were trying to figure out what to do if we did just ended the relationship. Now I don't have to worry.
I just have to scramble to get someone by next week.
I keep looking at the light at the end. So excited to see moral change. She brought everyone down.