From a woman's perspective, I think she planned it this way,ie..the food. She knew she was going to be gone with the kids and you were going to be there by yourself. She didn't see the need to stock up before she left to be nice to you. I'm not sure the message you want to send is "thanks for kicking me out. here's a full pantry." If you want to do something, offer to take the kids to your house when she gets back.
As far as asking for help, I think she may surprise you and take care of it herself.
