Parents gave my sister money for house deposit

[mooneus]

My sister is currently expecting her first child. Recently she moved into a 3 bed house with her boyfriend in a relatively nice area. I know on their salaries there was absolutely no way they could have afforded to buy that house. So after a bit of questioning I found out my parents gave her just over £10k for the deposit.

For the last year I have been working 2 jobs and living a frugal life to try and save for a deposit. And it feels like a kick in the teeth that my parents have stumped up that cash for her, just because she's pregnant.

Am I right to be annoyed at my parents for doing that? I understand the baby is now the priority, but it's not fair when one child gets preferential treatment.

Thank you for all your messages of support and for advice. I really appreciate them and each one I have read has resonated with me in one way or another. I am honestly very shocked and grateful.

For those who have said about speaking up, I have a few times but it has never ended well. My sister is constantly a victim so I think it makes my family sympathise her more and I look bullish or 'over opinionated'. Like one person said it is my mums money at the end of the day... it is just hurtful to go through. Someone also asked about why i do/but don't feel bad about my mum. I feel bad because i think she tries hard to be equal, but then again i don't feel bad because she's not equal. That is the centre of my horrible crux.
Again thank you for all your messages.
Anymore messages of enlightenment are welcome.