You don't "protect" your child by negging them and putting them down constantly. Even if her intentions are good, they're what the road to hell is paved with.
I see what you are saying and yeah I get it .. Mom comes off pretty strict .. but she also off loads her stress on her daughter.
Is she right for treating Mamori like that ... Hell no... Is her heart in the right place, maybe.
But I have got the feeling that Mamori and her mother rarely speak to eachother. The times we have seen Mamori's mother have been after A possibly divorce, where in flashbacks we have seen her far more supportive and happy.. clearly something happened between then and now...
I guess I should Explain the Lost in translation Pun 守り(Mamori) protecting , keeping...
TL;DR
Mom is trying to protect her daugher Maybe the Wrong way and Mamori has A name that means Protecting