Do you think I'm overreacting?

I been at my mom's house for weeks because she had arm surgery and I been helping her. I have two girls, one is 3 and the other is 2. My parents and sister favors the 2 year old. My mom gets annoyed when the 3 year old tries to talk to her or come around her and she gives her mean looks. At first I thought I was over thinking it... but My sister is doing the same... she constantly calls the 2 year old name... doesn't say anything to the 3 year old. She's picks up the 2 year old and shows love but not to the 3 year old. My 3 year old has been looking sad all this week... she follows me everywhere and she tells me she wants to go home. They show more love to the two year old and it's been pissing me off. I was also the black sheet growing up. My sister has a 6 year old daughter and she talks to that little girl bad but she shows more love to my 2 year old daughter. So I'm confused. I always give hugs and kisses to my niece and tell her I love her. So it's sick. I don't think I want to be around my family anymore.

Do you think I'm overreacting?
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