I guess my other issues would be that children learn how to be parents from their parents, so if she is an unfit parent, then some of that blame lays in grandma and she has some oligation lies with grandma and what makes her more qualified.
Again no medical reason given for the age difference so I have to assume she ment personality and responsibilty level, which I have to assume again would be in part to grandma, so what makes her more capable?