Yep, I agree. 12 weeks isn't very accurate. Yes a good sonographer can probably give you a 60/40 guess, but any that's worth their salt will tell you that it's too early to be sure.
If she's very experienced then sure it could be a girl. But I wouldn't go buying pink just yet. Apparently it's far more common for a boy to be mistaken for a girl than a girl being mistaken for a boy.