My yellow face budgie (who I am told might be female - see pics in forum), is 'humping' its mirror - is this normal behaviour for a female budgie or is it possible that its actually a male budgie?

My aunty's budgie does this and is female,i think they think it's a nice bird and try to mate it, but to be honest dont know the real answere

Not all that weird... s/he is trying to mate with the 'friend' (reflection) in the mirror. Mirrors are bad news and I'd remove it straight away. Especially if you are trying to tame them as they'll be more inclined to bond to their imaginary friend and can even get quite aggressive.