Hey guys! I have a situation, and I need you to tell me if I am the asshole or not, because I really don't know at this point.

So I (15f) have a sister (24f), who well call Maggie, and a mom (43f) who is both me and Maggie's bio mother. Maggie recently had a baby boy who is now seven months old, and the whole family absolutely adores him. My mom specifically is head over heels in love with him.

Ever since Maggie got pregnant almost a year and a half ago, she has been staying over at my moms house, and basically living with us, which I don't mind. She was going through some stuff, and I liked having her around so I could help her out.

Maggie works from 6:30am-3:00pm on weekdays, along with my stepdad, so during that time, I am home alone with my mom and baby boy, because my mom watches him while Maggie is at work. So during the day, I am the only one who sees what happens and how this affects my mom having to raise baby boy for most of the day. My mom also has insomnia but she wakes up at 5:30 every weekday so Maggie can go to work. Needless to say, my mom is always exhausted, but again, I am the only one who sees the extent of it because I'm the only one who is ever home.

During the day, my mom will complain about how tired and stressed and exhausted she is. She doesn't whine about it or anything, but it's still bad enough that I can see the effect it is having on her, and I hate seeing her like this.

Maggie, even when she gets home from work, has my mom watch baby boy for most of the rest of the day. She goes out to tan almost every day, and leaves my mom with baby boy for another hour. Another issue is that Maggie makes my mom (and I) do basically everything for her. She is very entitled, and gets pissy and cruddy when we make her do something for herself. She makes excuses like how she can't brush her teeth while holding baby boy or she can't wash bottles because she's already laying down with him. Basically all stuff she would have to do as a mom anyways, but is too lazy to do because she knows my mom will do it for her instead.

It's gotten a lot worse in the past three months, because she is now pissy and cruddy to me, not just my mom, and I am not as good at holding my tongue as my mom is.

Another thing, anytime my mom complains about being tired or stressed because of everything with Maggie and baby boy, I argue with her that she needs to call Maggie on her shit, but every time my mom just says, "Oh no it's fine, I'm just tired." I have had this talk almost a dozen times, and I will literally beg her to stand up for herself and tell Maggie that she is not her personal servant basically, but it's the same response every time. "Oh I'm fine I'm just stressed/tired."

About a week and a half ago, it blew up into a fight between me and my mom. It was just me, her, and baby boy in the house, but she brought up being really stressed because she was having to plan a graduation party for my cousin. I told her that I could watch baby boy for an hour or two so she could focus on getting stuff done, and if I needed any help, she would just be in the other room. She basically refused and just repeated that she was stressed and that she had so much stuff to do, but she couldn't do anything until the day of the party because Maggie would come through and destroy it. (When Maggie gets home from work, she just scatters her shit across the living room and will whine and gripe to my mom if she asks her to pick it up, and then goes to bed without picking it up. I have started picking up some of her stuff when she gets home just so my mom doesn't have to deal with it, so that's what my mom means. If we clean anything, Maggie will mess it up and make us start all over, but she doesn't give a shit about it)

After my mom made that comment, I kind of lost it. I started arguing with her that she needs to stand up to Maggie and stop letting her treat her like this, but my mom got mad at me and just said I was the one stressing her out now. I told her that she wouldn't be so stressed if she made Maggie actually do something and not make my mom raise baby boy 75% of the day. I started crying and told my mom about how I see what Maggie's actions are doing to her, but my mom just looks away from me and says she has never said that to me, and that this has done nothing to her. She complains at least 2-3 times a week about this.

She said that she was scared Maggie would take baby boy away and not bring him to our house anymore (she is renting an apartment, but doesn't actually live there, but will go there if she wants too). I told my mom that would be Maggie's fault, not hers. Then my mom yelled at me and made me promise I wouldn't say anything to Maggie, and said, "I'm sorry you don't think that what I need right now is the right solution." Aka letting Maggie continue to treat her like shit so she can continue to see baby boy.

Like I said Maggie has started treating me the same way in the past few months, and gets mad when I stand up to her, then goes to complain to our mom about it, but my mom usually sides with me, just never outwardly bashes Maggie so she won't get mad.

I'm stuck between a rock and a hard place. My mom still complains about the situation, and I have just started saying, "Well you know my position on the issue," and then changing the topic, just so we don't get into another fight. But if I keep encouraging my mom to stand up to my sister, even though she has told me that is not what she wants, am I the asshole?

Please be honest with me, because I just want what's best for my mom, and I hate seeing her be treated like a doormat by her own daughter, and be ok with it just because she doesn't want to make Maggie upset.