I would wonder if the hotel has rules about cooking in the room...it may be a better idea to give her gift cards to local places to eat. They may have rules that nothing is allowed that can not be microwaved.
Some other ideas are to take her laundry to wash and dry, to give her a break from the small space by inviting them over to hang out, maybe a movie night with all the trimmings, or by borrowing the kids for a couple of hours for some reason or another. Having alone time is something we all take for granted in our own homes.
I have a friend who is a single adult, she is in her 40's and handicapped. She had a family but they were killed by a drunk driver. She hardly ever gets invited to any activities by our "friends". I feel very guilty over Thanksgiving. My family was invited to a friends home for the day but this other single friend was not. Even the missionaries were invited to the other friends place for the day. I didn't tell her we were invited, I did not tell her we had plans, nothing. I let her think we didn't really do anything.
She sat all day with no one even calling, no one even bringing her a plate of food. No one cared enough about her to give a D*^%$#m if she felt left out or unloved. I have this guilt about how I treated her but I honestly did not want to hurt her feelings by telling her we had plans or what we did. I may have hurt her even more by not saying anything.
The reason I told this on myself is to show why I would do different things for this family than the "regular" ideas. They need to know they are cared about, more than "Ohh, you poor thing" that some people might do. Not you of course, you are trying to come up with things to do that will help.
So, do things that will show her she still has worth even though she isn't working and supporting her children, that the state is making it possible for her to not live in her car with her kids, etc....these are the things she is thinking and she will most likely hear from people. Her self esteem is suffering right now, her self worth, etc...she needs to remember she is worth something.
I would also find out if she is willing to take on odd jobs, like helping someone clean their house or decorate for Christmas, maybe even clean the house after the holidays. If she is willing to do these things and it won't mess her up with the state by showing she has an income then I would be calling everyone I know or finding things around the house she can do for me.
One thing that could be done is to give her a gift card instead of cash for work done. I clean my FIL's house once a week and he gives me an allowance on the gas card. I can use however much I need but if I go on vacation or out of town we try to plan it on months he is not traveling too. I talked to the guy doing our taxes and he said it wasn't really income and he was not going to add it on. Giving her a gift card to Walmart or some other place might be a way to get around paying in cash may be a way to go.