Friends or not friends?

I have a friend who tries to put me off doing things, i always wanted to go in fire brigade, at the time i was working with her and she said things like "its really hard to get in" "what if you find kids burnt dead in a car" which i understand are possibilitys, and it put me off at the time, thing is tho id rather try to do it and be in that situation before i make judgements on how id react, otherwise ill regret it the rest of my life if i didnt, so im going for it now, then she says something about my references not going to who its meant to as i said id put my nice boss down, implying that it will go to a horrible boss, why is she doing this?