No. Blog over.
Just kidding, but lets get real.
If you really want to do it anyway you need to be ready to lose your friendship.
You're probable in one of three situations:
1. She met you and you were straight and she still believes you're straight, but you looked up one day and realized you were madly in love with her.
2. She knows you're queer and maybe thought of it as a possibility but never seriously considered a relationship with you.
3. She knows that's your testimony, as in you used to be gay but decided to not be anymore for God, and has been flirting with you and there's something between the two of you.
I have been in all of the last two situations and none of them ended in a life long relationship. I am still single.
None of those ladies are close friends of mine anymore, although I love all of them dearly.
This is my advice to you:
If you feel that you cannot live another day keeping this secret from her then go ahead and share your feelings with her. And then be big enough to give her space to process. Do not ask her if she feels the same, if she does she will tell you without you asking.
Be ready to answer all of her questions. Like, "how do you know?", "how long has this been happening?", "does anybody else know?", "when we had a sleepover and slept in the same bed were you in love with me then?" etc. Answer all of them honestly, because if the friendship ends you'll want to know that you told the entire truth and that will help the healing process go a lot faster.
You can tell her face to face or write a letter or send a video message and have her either read it or watch the video while you're there with her.
I pray it turns out well, but if it doesn't at least you told your truth and loved.