My Sister Hasn't Left the House in 10 Years—Should I Be Worried

TL;DR in the End.
Me (18M), the older brother of three, have a sister (17F) who is second to me in age.

My sister hasn’t gone out of our house for nearly 10 years now. Yup, you heard it right—it’s been that long since she went out on her own. It has been 10 years since she visited any shops or bought anything herself. The thing is, if my parents wanted something, they would tell me or my younger brother, so she slowly stopped going out because she had no need to. My parents didn't restrict her. Except for school she doesn't go out which we both go together. If I don't go. she doesnt too

But that’s not it.

I feel like she is very disconnected from our generation. She doesn’t take pictures, nor does she know how to take them. She has no idea about current slang, doesn’t listen to music, and doesn’t use social media. Yes, no Snapchat, Instagram, Pinterest, or even YouTube. I’m not exaggerating. I bought her few books to read but she didn't read them.

All she does is watch cartoons with our 8-year-old sister. It’s like she lives under a rock. She doesn’t know anything happening globally. Her knowledge is limited to what’s in her schoolbooks. The only time she watches Dhruv Rathee is when I put it on the TV. Other than that, all she does at home is study and watch cartoons. I feel like she is scared of growing up. Her habits and mentality haven’t changed since the lockdown in 2020.

She doesn’t know how to use UPI or do other simple tasks. I created a Quora account for her a year ago, but she said using a phone makes you “chichore” or something like that. She lives in her own mental bubble which Im afraid may burst anytime soon

She also doesn’t do chores. She doesn’t do anything you’d expect from a teenage girl. My parents scold her almost every other day for not doing her share of the work. My mom gives her one small task a day, and either she does it wrong or doesn’t do it at all, every single time.

She also gets mocked by our relatives and siblings for being dark, short, and chubby. I regret admitting that I joined in on the teasing in the past, but I’ve apologized for it and feel bad about it now.

I made a post about her a year ago Here , and to this day, she’s still the same.

I’m really concerned about her. I don’t want her to get bullied or face ragging in college.

What things should I do? I really need advice

Or am I just worried for nothing?

TL;DR:
My 17-year-old sister hasn’t gone outside on her own in nearly 10 years. She’s disconnected from modern trends, doesn’t use social media, No knowledge of things, is scared of growing up She avoids chores, gets mocked for her appearance, and hasn’t changed since 2020. I’m worried she won’t adjust well to college or adulthood. Am I overthinking this?