Would you give the money back??

A friend and myself decided to rent a house together. We agreed to split everything. We both put down half of the deposit and half of the first months rent. We get the keys and move in. Everything is going great. Three weeks in, I get a text at work from her asking how upset would I be if she moved back in with her ex. I told her I would be a little bummed but understand and want her to be happy. She responds with I love you, you’re truly the best. Thank you for being so understanding. Well I got home that afternoon and she had moved out. I was totally shocked and didn’t know she meant right at that moment. I didn’t want to be a bad friend so I didn’t say anything. Two months later at lunch today, she out of nowhere asks me when I’m giving her her half of the deposit and first months rent. I was shocked. I’m glad it worked out with her and her ex BUT it really put me in a financial bind and I wouldn’t have agreed to a house together. Do you think I should give her the money back? I’m now having to cover her part of rent and everything we agreed to split. I honestly don’t have it to give. What would you do?