Mariah actually reminds me of a friend of mine. Growing up, her dad was absentee, but her mom took great care of her. I always thought her dad was a jerk, but my friend thought the sun rose and set on him despite the many times he failed her. I don't think she realized what a gem she had in her mom until her mom passed away.
Meri was Mariah's primary caretaker, and there is no way in the world Mariah would have gone to a private college without Meri's financial support, but Mariah has never evidenced any gratitude. She has never said a word against Kody and seemingly had no problem wit