The biting is not permitted and it would be a good idea to stop some privileges for it ...
Try to emulate what your mom is doing ask mom what games she lpays, maybe they have a good time, all you have to do is be the same as your mom, its great your daughter has such a good relationship,with her Gran, so copy them ,no confrontations pay her attention, games and fun, you will find she will reciprocate ....
hi,
it is very hard to enforce your role as mum when someone overrules you all the time!
i have had similar problems with my son when he comes back from his fathers,he doesnt take any notice of me, its like all my hard work has gone to waste!!!!
I would suggest speaking to your mum, maybe having some boundaries like' i know you love your granddaughter ,but you have to respect my wishes and my way of parenting'
Good luck with that..be strong..love to know how you go..