Need advice

My little sister is 11 we’ll call her E. And my husband has two sisters around her same age so when we got together they became close. Recently his little sister reached out to me (she’s 13) we’ll call her M and asked me if something is wrong with E. She had just left from spending the night with me and went back with my mom and I think my mom her and my little brother to six flags. So I wasn’t sure why something would be wrong. So she shows me a couple of concerning things from her instagram (I didn’t know she even had an Instagram) and her Instagram name says she’s broken. And these are some of her posts (that M showed me)

And this is a conversation between M and E

M told me she’s cutting herself and I’m really worried

This is where it gets long and complicated. I want to tell my mom and ask her to talk to her and look into counseling. But I really doubt my mom would bother listening and just get mad at her and make things worse. That’s what happened when I was younger and was feeling sad.

My mom is narcissistic and my little sister has her dad but he wouldn’t really know how to help. I’m going to just list out my moms characteristics so you can get a bit more insight:

-she creates problems and pushes people away

-she treated me like I didn’t have feelings my whole life

-told me I was ungrateful ever since I was little(toddler age)

-always compared me to bad people

-always talked to us about her problems with my stepdad and told us so many negative things about him. Now that I’m older I see she’s the problem and not him

-she fought and argued with him daily around us if she wasn’t fighting with him she was fighting with me. She hit him on the back with a butcher knife, thankfully it didn’t hit him with the blade but flat and just broke off the handle. She admitted to meaning to cut him and not sure how the knife hit him flat.

-she said if he ever “tried” something can’t give you an example of what that means right now cause I can’t remember. But anyways, said she would ruin his life by beating herself up and saying that he hit her ect...

-she was physically and mentally abusive towards me. Wasn’t that way towards my 2 siblings though

-she would pick fits with people out in public that would scare us and put us in danger (driving recklessly ect...)

-make up things/lying manipulative

-she would take us to see this man that she thinks is Es (my little sister)s real dad. She’s been taking her to see him since she was younger and still takes her to see him to this day. I know he gives my mom money and I also know he sells drugs. Also my step dad (Es dad) lives with my mom but practically every week or other day she’s throwing him out. My little sister would call that man dad and go home and call my step dad dada.

-she scares them with the way she yells at other people or when she starts yelling at me

-if I disagree with her or say something she doesn’t like she tells me to have a nice life and tells me to never talk to her again

-She blames me for everything and calls me a horrible person. It took years to figure out what was right and what wasn’t because of all the gaslighting and manipulation

-When I was 18 I tried talking to her about my dad sexually abusing me she told me I was lucky he didn’t stick his dick inside me even though I never mentioned anything like that. She said a couple of other things that admitted she knew something was going on but just never said anything. My dad also sexually abused my aunt (my aunt was a preteen at the time) and my aunt told her. She didn’t do anything.

-She recently told me a couple of days ago to call my dad (he’s in prison has been for many years she would take us to go see him) she told me to call my dad because even though he did what he did to me I probably still love him more than I love her. And i was just disgusted

-she gets jealous a lot. I can’t help anyone with anything because then she says I don’t do anything for her

-she’s obsessed with keeping up with appearances, when my little sister was losing baby teeth she wouldn’t let her smile with her mouth open

-we were always in trouble for something.

-she didn’t hug me much at all growing up

-she would have me stay up for hours on school nights giving her back massages

-she’s not talking to me right now because I have nothing to offer her. But I can guarantee you when I’m successful she’ll talk to me.

-at a funeral (at the time she was upset with me over I’m not even sure what) I approached her because I wanted to be with her and she walked away from me.

-she’s really good with my siblings though. Didn’t treat them that way. After she had my little sister she acted like more of a parent. They hug and are affectionate. And she seems a bit obsessed with how “sensitive” my little sister is. And she doesn’t yell at them that way, but they are around all of the negativity and she does tell them about her problems with my stepdad

-she’s always taking them out and always buying them things like she’s trying to make up for something. She has a spending problem. She’s at the store every single day

I have a lot more. But I’m going to stop there because this is really long.

I just need advice on how to go about this situation, I really want to help my little sister. But this is a really sensitive situation. I don’t want to make the wrong decision.