Do some research on here. You'll find out as much as anyone can tell you.
bmi is currently in the process of being sold by Lufthansa. At the moment, it's not clear (or decided) who is actually going to purchase it. In the case of mainline, it looks as if IAG and Virgin are now the only two after it. Lord Hesketh was interested, but he's pulled out now. Contrary to reports, it is not a done deal with IAG.
Baby and regional are both being sold seperately, but if those deals fall through, then I suppose whoever buys the group buys them too.
I have no idea who's actually buying Baby (well, I do, but I ain't saying here) but if it is sold, then I think that's the best thing for the company. I can't imagine IAG or Virgin being much interested in it.
As a first job though, I would suggest that you don't be too choosy. If you are offered something, then take it. It's only if you are offered multiple jobs that you need to think about it.
Baby is full of top notch people and you wouldn't go wrong one little bit by starting your career there.