Friend cancels most times

This past year, I became friends with a woman. We make plans, most of the time it's her idea, and she usually cancels last minute. It's frustrating because I do want to spend time with her, but it rarely happens. On Monday, we made plans for Tuesday, 30 minutes before we were to meet, she cancelled citing food poisoning since the middle of the night (been there, it's not fun). Her usual excuse is that her neighbors kept her up at night and she didn't sleep well or that her husband came home early so that they could do stuff. It sucks because I could be making other plans for my days instead. I can't help saying yes to her because I know she needs a friend and when wet finally get together, it's such a nice time. She's always very apologetic, says she'll make it up to me. She is a very kind person who I want in my life, but it's so difficult. What would you do?