Bin her.
If she's complaining now then just wait until you start your training. It's a full time commitment and she has to be in on it.
If you 'pick her' then you will just become bitter towards her later on for missing out on a dream you had while she goes off on a career direction of her choice.
You never know she might be bluffing and will come crawling back if she realises your not going to back down (this never works for me)