Re: Is it possible for someone tech savvy to hack an Apple device?
My advice is this.
Do NOT get any device that requires biometric access. The issue here is beyond device and her safety both physical and mental. As a friend do her a favour and seek help for her. People are very easily programmed, and although the pain she is suffering is obvious o everyone outside of that relationship, in her own mind she's justified it and its that which needs to be dealt with. If he's tech savvy and watches her online conversations etc then placing a barrier between him and access to that information will make it worse for her in that he can grab her finger while she's drunk or asleep and open the device or threaten physical harm to do the same if its a password.
The issue is deeper than which phone, the relationship exit has to be secured first. If she has access to a laptop/desktop I suggest setting up a free email like gmail or outlook etc and only accessing that email via a web browser with 2 step authentication and making sure she logs out afterwards.