The 20-year-old is marrying Nick Gordon

Whitney Houston‘s daughter Bobbi Kristina Brown got angry on Facebook yesterday after revealing that she’s engaged to long-term love Nick Gordon.

Some fans think it’s wrong that Bobbi, 20, and Nick, 23, are getting hitched because late singer Whitney took him in when he was 12, although she never formally adopted him.

‘YES, we me nick are engaged,’ wrote Bobbi.

‘I’m tired of hearing people say “eww your engaged to your brother or if Whitney was still alive would we be together or would she approve of this.”

‘Let me clear up something, we aren’t even real brother and sister nor is he my adoptive brother. My mom never adopted him.

‘In fact, mommy was the one who even said that she knew that we were going to start dating.’

Bobbi – who’s the daughter of Whitney and R&B singer Bobby Brown – was said to be ‘in hell’ after her mum drowned in her bath at the Beverly Hilton Hotel aged 48 last February.

She and Nick hooked up soon after and Bobbi is sure that Whitney – who she was very close to – would be happy for them if she were still alive.

‘My mom knows me better than any of you. You may or may not agree with my relationship. You may or may not respect it. Judge me, go ahead,’ wrote Bobbi.

‘Your opinions are yours and mine are mine. It is my life and not yours. The decisions I make have nothing to do with you. Goodnight.’

SEE PICTURES Whitney Houston: Her life in pictures 1963 – 2012

SEE PICTURES Whitney Houston in Celebrity Deaths 2012

SEE PICTURES Whitney Houston‘s funeral service

Anna Duff