Seeing someone’s true colors

My mom had a rough childhood & decided to have kids & continue that cycle x10…She was a great provider. We traveled often, lived in beautiful suburban homes but she was very abusive physically and emotionally. So growing up I lived on and off with my grandmother. (My mom’s mom) I had been on my own for the last 5 years and had to recently me and my toddler move in with my grandmother. I always thought highly of her & had a good relationship with her up until now… she chooses favorites with the grandkids.. she’s bringing my aunts kids out for Halloween & didn’t include my daughter.. they had a party for my aunts daughter, TALKED about it infront of my daughter & didn’t invite her… when my aunts kids come over she’ll hug them & pick them up but sometimes doesn’t acknowledge my daughter… I’m also beating myself up over it because when I was living on my own my gma would watch my daughter often & I never knew this was how they were treating her.. she was younger at the time so consciously didn’t know but still… I’m living in her home & working on getting out of here but disgusted this is who she is & the weird part about it is she’s 1 out of 6 sisters & has always talked about being the black sheep of the family yet she’s doing the same thing to me and my daughter… why wouldn’t you invite your other granddaughter out for trick or treating? Why wouldn’t you bring her to a kids party…? It’s sad learning this about her. Not to mention I’ve brought it up to her & now it seems like she does it purposely.