Dodgy, Aimiloo, the word is 'dodgy'. Come on, we're all thinking it!
jbly...as an immigration consultant who has been reading this thread with continued amusement, I think it is now time to nip it in the bud.
If your 'friend' wants to come to the UK, the only options are a) a student visa b) if she is currently a student then she could apply for a BUNAC. You can't employ her to sing for you, as you wouldn't get a work permit. You can't apply for a fiancee visa for her, as this is going to be an obvious lie if she calls you and your partner 'mom' and 'dad', and there will be no evidence of any kind of romantic relationshp (one asusmes from your posts). The UK does not recognise adult adoptions, and basically I second everything that everyone has said. Lola's post, copied below, was absolutely right.
I have no doubt that you will come back with more questions, but the chances are that you will receive the same answers as before.
Vicky