Good God, this has got to be one of the tackiest things I have ever heard of. Asking people to sign up to bring you food? If you get some, be grateful whenever you get it. If you can't use it that day, stick it in your freezer until you need it.
It is assuming, whether you set it up or make it seem like it's coming from your mom. I'd have trouble not laughing at whoever asked me to sign up for something like this, and I'd be less inclined to do something, because it's just so darn presumptuous. People shouldn't feel obligated to help you out, and that's what something like this does.
This. ALL of this.
My FRG does a thing like this for new mothers, people that have surgery or a death in the family, etc.. It is NOT put together by the MTB or her mother/sister/whatever. It is BEYOND presumptuous to assume anyone wants to come bring you food and it is plain rude to tell them when to do so.
Personally, I would never just show up at a friend's house after she's had a baby without asking first if she is free or up to a visit.
Please do not do this. Please do not ask your mother (or anyone) to set it up for you. If someone volunteers to set up a meal train, then that is a totally different story.. you don't ASK for it. And please please please do not post anything on facebook/twitter/IG.