If she’s using androids she most probably likes the big screens. I’d recommend at least get the 13 (like everybody else said).
The SE caters to a niche market of people who absolutely have to have an iPhone and either don’t want to spend more or need the Touch ID. No happy android user is going to like an SE (at least the current one) because of its small IPS display and abysmal battery life. (Leaving aside the camera which is decent but nothing to be happy about). No matter how good the processor is, the phone feels extremely dated and looks like it’s already 7 years old out of the box.