my sister records in secret

My younger sister ‘A’ (13f) and i (20f) haven’t always had the best relationship. I have autism, and i’m schizophrenic and bipolar (only recently diagnosed within the last year), so i didn’t have any support, medicine or any help growing up. Things were rocky when we younger, but things have gotten very better.

For context. We don’t have the same dad, she has no contact to her dad that she shares with our younger sister, and she often talks about how she envies me and is jealous that i still talk to my dad and maintain a tolerable relationship with him. (My dad and i haven’t had a bond in years and first in the past recent years started talking again. It’s been hard for me, so hearing her portrait as if my dad is a saint hurts me.) Also, she had a hamster that my mom and i got her after she passed a sort of ‘helping class’ in Maths. She loved it. But since she didn’t want it anymore after a few months of us getting it for her, we gave it to my other sister who’s younger than us both, but still in the same house and all. I live temporarily with my mom and them while i look for a new place, and in the house we’ve always shared responsibilities with our pets like feeding them, taking care of them and such. No one stands with the sole responsibility alone.

Earlier today, i was making food and ‘A’ came down. I asked her why the hamster’s water was empty, she said our younger sister must’ve forgotten to give it water. I asked why the hamster hadn’t been outside the cage for a while to roam around and such, and she said our younger sister hasn’t done it. I told her she could’ve done it too as it’s her pet too and she said “It’s not my problem anymore.” I got a little angry, and said she needed to grow up with her responsibilities of taking care of pets or i would for sure not feel safe putting any of my future pets in her care if this is how her mindset was. We don’t argue often, but she’s been with her friends a lot lately.

She went onto snapchat i saw and clicked record and locked it so you didn’t have to hold down the button and turned her screen down towards the table, thinking i didn’t see it. And then asked “what were you complaining about?”. I confronted her about it and said “i know you’re trying to record me, im not stupid.” and she just glared at me and walked back to her room.

I have a feeling she takes the chance to record conversations and now i feel like i can’t trust her or any in the house can trust her anymore. She’s a lot online with a specific group of fans for some singer, and i feel like they have some grab on her. I once had online friends and they ‘brainwashed me’, and i don’t want the same thing to happen to her. I’m not saying all online friends are bad, but i haven’t heard good about hers. But she gets defensive against my mom and i, and im not sure what to do. I feel as if all my trust for her is gone when she tried that stunt on me. What do i do?