It's all very well saying 'its her decision, let her make it herself' but this assumes she has all the information she requires to make that decision.
She doesn't, and she cannot, because she is 16.
To my mind and with the hindsight of being 19 and thoroughly unprepared and pregnant (which ended in a miscarriage) - better an abortion you regret, than a child you regret.
Yes, regretting or even not regretting just living with that decision, is hard.
But living with, raising, loving and caring for a child you now regret, weren't prepared for, weren't equipped to raise... thats MUCH much harder. And being that child... yeah thats horrible to live with.
Having an abortion is horrible now, but compared to a child you don't want and struggle to raise (even if you come to love them as many will) is long term hardship for everyone.
Kids in this situation want a reset button, a 'back to normality' and there isn't one, you can't rewind the clock and neither of the available options are anywhere close to it.
So whilst she shouldn't be bullied, she should be strongly supported to have an abortion and she should have someone explaining to her very clearly and possibly a little bluntly just HOW hard raising a baby will be and how thats going to totally alter her plans.