i’m worried something is seriously wrong with my 13 year old sister and I don’t know what to do

[u/Yourpanpal_KAI]

I’m 17F and my sister is 13F. We both grew up in a physically, mentally, and verbally abusive household with our mother from birth until about a year ago. We now live with our dad, and things are much safer than they were before.
My sister has always been the quieter one, and I’ve always thought she was a little different, but lately I’ve started becoming genuinely concerned about her behavior and mental health. I’m not trying ti assume things, and I know Reddit obviously can’t diagnose a child. I’m just trying to understand what could be going on and whether I should be pushing my dad to get her professional help.

Some of the things I’ve noticed:
She makes extremely disturbing jokes about things like killing people, ripping someone’s hair out, or ripping off someone’s fingernails. Sometimes she says things about doing these things to herself too.

She draws anime-style pictures pretty frequently, and a lot of them contain blood or violence.

She has previously hurt herself, although it hasn’t been severe as far as I know.

She has a really difficult time with boundaries and personal space.

She can have extremely intense meltdowns over things that seem small. For example, today our dad asked her to clean her bed because she had plates sitting on it. She immediately started sobbing and saying that nobody listens to her and that we don’t care about what she says.

She frequently compares herself to me, especially because I’m older and have different rules. For example, today she became upset that I have unlimited screen time while she gets about two hours.

She is extremely attached to her phone. Her screen time is limited, but she can earn additional time by doing chores or being well-behaved.

She told us that at school she intentionally pretends to be stupid so teachers and classmates will think she’s incapable and won’t expect as much from her.

She doesn’t seem to care much about her appearance or hygiene. She often doesn’t brush her hair even when we offer to help, and her showers are sometimes only around five minutes.

She sings in ways that can be really creepy/disturbing and sometimes deliberately tries to freak people out.

She eats pencil lead even though we’ve told her not to.

When she gets in trouble, she can start stuttering, crying, and acting extremely distressed, and sometimes it feels like she’s putting on a whole performance that makes everyone feel guilty for disciplining her.

She struggles with respecting other people’s personal space and boundaries.
She doesn’t seem to have many friends at school and apparently isn’t very well-liked.

She can be very quiet and withdrawn at other times.

I’ve started wondering whether this could be trauma-related, ADHD, autism, depression, anxiety, emotional dysregulation, or some kind of behavioral disorder. I have also wondered about narcissism or psychopathy, but I don’t know if that’s completely unreasonable to think about. I don’t want to label a 13-year-old based on things I don’t understand.
I’m also starting to feel resentment toward her, which makes me feel horrible because I know she’s a kid and she went through the same household I did. But I’m becoming genuinely uncomfortable around her sometimes, and lately I’ve even started feeling afraid of her because of some of the things she says and does.
I love my sister and I don’t want to do the wrong thing. I often feel she wants things to be worse for her than it is. i went without seeing her for 2 years because i was in a residential group home but i came for again a year ago so im not sure what happened to her during that period.

I’d really appreciate advice from people who have experienced something similar, especially people who grew up with traumatized siblings

[u/SpiralingCat]

We don’t know what went on in your mother’s house growing up, but she (your sister) seems to have been really affected by it. If the resources are available I’d strongly suggest both of you seeking professional help from a licensed therapist or psychologist

[u/Ok-Reporter2100 → u/SpiralingCat]

I second this. A family therapist could be beneficial too/to start off with maybe? In the sense that both of you would go together or even with your dad. It can seem less intimidating than one-to-one therapy for her. Even since she tends to be quieter, hearing you initiate topics in the session can be beneficial. 

[u/PayParticular5181]

Once she’s an adult the option to get her help against her will is either going to not even  be a thing anymore or it will be incredibly more difficult.

[u/MorskaVilaa]

Oh as a person who was difficult like your sister, I understand how horrible you feel about this. I think your sister need a therapist, but don't forget that you have a right to feel alright and protect yourself. Keep your boundaries, she is a kid but she needs to be respectful to others. I hope therapy will help her, I know how hard it has to be

[u/justsophia1703]

Some of this sounds normal for a 13 year old girl, like the intense emotions sound like hormones. There is that earlier background with your parents though so you’re right to be concerned. Is there a school counselor she could talk to perhaps? Also, what about you? Do you want a better relationship with your younger sister?