So two weeks ago I found out that I have a half sister. Turns out that my dad had a baby with a woman a couple of years before he met my mum but he gave up his rights to her in order for the baby's step dad to adopt her. Twenty years later and this girl has turned up claiming to be his daughter. My dad told her that he did not want anything to do with her as he had his own family now, but a few days later the he changed his mind claiming that he feels guilty about the entire situation.
The thing is, he kept this child a secret from my mum for 26 years, and to be honest they are now on the verge of splitting up because of it. My mum has basically come out and said it's either her of his daughter.
A small part of me wants to get to know this girl, and I am genuinely sorry for what my father has done to her. But a bigger part of me cannot help but hate her for all of the trouble she has caused by turning up in my lives. She turned up at my dad's work place and told him she was his daughter, she has even said that she has been to my place of work before she even got in contact with him. She is craving a relationship with my entire family and my mum just can't accept that. I don't even know if I can accept that. I know a lot of why i am feeling this way is because I'm very close to my mother and not my father, but right now all I can think about is how this girl has ruined my family.. I know I'm being a cow but I can't help how I feel.
I can argue that I'm 22, and that if I want a relationship with her then it's my own choice, but I know that if I start anything with this girl then it's going to crush my mum. I'm certainly seeing my dad in a different light for giving up his baby, but he kept the fact that he's had any contact with my half sister secret for the past two weeks until my mum saw him talking to her on facebook. It turns out he's been texting her and talking on the phone to her for two weeks.
The more time that passes, the more conflicted I get on how I feel about this girl.
Any advice on how to deal with all of this?