She might also feel afraid (Is Mom okay?) or excessively dutiful (I belong to Mom; it’s my job to protect her and keep her happy). This child may grow up to feel she’s betraying her mother if she has other interests or friends or wants to move away.
My mother did this and I ended up feeling like I had to hide my life from her and ended up leading a double life as a teenager (starting as early as 12 years old).