Trying to find my sister is harder than I thought...

Last year my mom spilled some news I should’ve been told a long time ago. I have a sister.... my dad got a girl pregnant right before him and my mom got together or right after they broke up. She said she knows it wasn’t while they were together for sure. The only thing I know is that my sisters mom is a blonde.... I have no clue what any of their names are and it’s killing me. I’m not supposed to know I have a sister. My dad was supposed to tell me but since he hasn’t my mom decided it was killing her inside so she had to finally tell me. So it sucks I can’t just ask a family member that might know. I also went onto Facebook and looked at his friends and he has TONS of blondes on his Facebook..

I always knew I wasn’t the only child. I also found out when I was 7 I had a half brother also.

I just want to know who my sister is and if we would bond. 🤷🏼‍♀️ wishful thinking????

Also I don’t know where to post this. So please don’t yell at me for posting this in the wrong place lol 🙇🏼‍♀️