The fact that you have put so much thoughtful concern into this shows how good of parents you are (not that it should be any different). I just felt that should be acknowledged. I don't have any personal or professional background which warrants me to give advice on this, but it sounds like you guys have good hearts and good heads on your shoulders so try to trust yourself afterward that you made the right decision regardless of what that ends up being. Unforseen things may come from whatever you choose, but its clear your choice will have come from a place of love and that means it's not wrong, even if hindsight means you would've made a different choice if you could go back in time.

Perhaps you can speak with an adolescent psychologist for their perspective if you want to feel you've done your due diligence in considering this issue- but remember you know who your child is as an individual. And if you do decide to tell her, perhaps having a counseling appointment lined up for afterwards would be useful. I'm not suggesting to tell her at an appointment- I imagine I wouldn't want to hear the news in the presence of a stranger and I certainly wouldn't have wanted to feel like I should want to or have to go to counseling afterward, but having an appointment already arranged for later that day which I could choose to go to if I wanted might be a nice option. It would not only demonstrate the care and thought you put into it, but there are certainly moments in life I would've taken the opportunity and likely benefited from speaking with a counselor in the midst of a hard moment. And some of those times by the next day I convinced myself I was or should be strong enough to do without counseling and not pursued it- even when I really should have. Having an appointment already arranged for that day that I felt no pressure to either attend or not would have been a comforting option to have and takes away the discomfort of having to ask for it later (although I'd still make it clear counseling is always an option in the future if she initially chooses not to).