my SIL she's not allowed around my daughter again after she humiliated her over food?

My SIL is very hard up right now and has been going to food banks to feed her, my brother and the kids. She works part time and takes care of my brother (car accident, partially temporarily paralyzed). They are waiting for insurance to kick in to pay for his medical bills, an on call nurse and PT. Since she moved to part time and is hard up with money, she offered to babysit my daughter (11) for extra cash. I offered to give her $250 a week, day care prices. She agreed.

Now, since I know they have been going to food banks, I have been providing my daughter food every day I send her there so my SIL doesn't have to worry about it. Usually a couple sandwiches and snacks. However, I get a text from my daughter yesterday saying my SIL humiliated her and made her feel stupid over taking food. I guess my daughter was still hungry after eating all the food I packed (she just had a ADHD med change and I guess it peaked her appetite) and she went inside and ended up eating a bunch of food and my SIL lost it because it was "all they had" (they were having a pool party so everyone was outside and didn't see her take the food). Told my daughter to get outside. So I immediately leave work and come to investigate and find my SIL inside with her head in her hands. I ask what happened and she wouldn't even look at me. I start prying for an answer because my daughter is visibly upset and practically ran to the car when I got there. She snaps and says "go ask you kid how much she fucking ate Chrissy, AFTER I told her not to touch what little food I had. Go!" So I told her no, you tell me, you're the fucking adult. Well, she literally dumped out an entire full size packing box of empty containers. Cracker packs, like 4 fruit containers (strawberries, blueberries, raspberries and watermelon), pudding cups, bags of chips and an empty sandwich meat bag. It was a lot and I'm not saying it wasn't. But then she goes "want to see what I have left to feed my fucking family?" Opens her fridge and it was basically bare. Now, in no way am I condoning it because that was absolutely a lot of food but I still think it's fucked up that she made my daughter feel like shit about it. I told her my kid wouldn't be going back there at all and she said "good. Your kid just knowingly took at least 3 fucking days worth of food from my kids mouths so I'd rather not see her anyways." My mom says I'm an AH because I knew my kid has a big appetite and didn't pack more food for her, which apparently makes this my fault and says that I should offer to buy them groceries, which I won't do. I guess she went grocery shopping for them following this.