I see a few issues here.
First, is snooping through her iPhone. Is she aware of this? Is there an agreed upon understanding that what's on that phone is for you to look at? If not, the first issue is one of trust. A teenager with a snoopy parent is likely going to open up a lot less once they find out. So you're going to have to broach the issue carefully.
Secondly, I think it's maybe just time for a talk, in general, about relationships and sex and being 14.
Finally, I think you need to really think about how you truly feel about homosexuality. You seem OK with it (which is great if she is, as having a parent that will support her is important) but I sense a few doubts there (well, as much as one can sense from a post on StackExchange...)
Good luck. Teenagers aren'tare a challenge no matter what!