Can adopted sister have rights to mom’s estate?

So here’s a doozy. I found out I have a half sister that my mom put up for adoption before I was born. Thanks to ancestry this person has found my mom.

My mom and I are not close and she doesn’t have a will. She’s 83 lives in CA. My sister made it clear she wants a relationship with my mom and not me. In fact her behavior leads me to believe she wants money.

I know there’s not much I can do about it now but just wondering what rights she has?