I feel like this thread is a reptile version of a Jerry Springer episode..
We're either missing a big part of this story or your mom has anger issuess. Something just doesn't make sense.
Anyways, lead by example with feeding your snake a proper meal and hopefully your mother will follow suit.
My MIL is just super controlling I guess and isn't as well educated on snakes as she thinks. I will feed my snake my way but also take care of hers with the same respect until she understands...