Friend troubles

So I have a friend(using this term loosely) that randomly starts messaging me and it mostly when her life is in shambles. Right now her boyfriend left her so she has no one to watch her kids while she works (not his kids). She just keeps talking about how she’s going to be out of work etc etc. I know she’s waiting on me to volunteer to watch them for her, for free. Her cousin offered to watch all 3 for 180 a week but she doesn’t want to pay anyone. I work also but I work part-time from 6pm-12am. Me and my husband have yet to have children of our own so right now we just enjoy each other. Am I wrong for not offering to watch them??

When the first one was born she was 17 and I was 19. I offered to help when I could but it turned in to her getting mad when I had other plans or even when I got the flu.

Any thoughts/ ideas?