Here's what you do.
Tomorrow tell her your mother said she's not too sure about her because she fell for her (mother's) bait, and that shes not too sure about her because she was trash talking her son, and that she told you that you might want to re-think her because she said nothing positive about you.
"you really thought she was going against her son? she was baiting you and you fell for it, now she don't like you too much"
after she fumbles and bumbles, that won't happen again, and you can come back here and thank me later.
my mother talks a gang of shyt, first time they tried to tag team me, I stepped on that real quick ^, now they both defending me against each other