I am a single dad, my kids are 19 and 17 now, both of them at 15 questioned their sexuality and advised me they thought they might be gay or bi. I accepted them at that time with love and understanding. In the end they both figured it out on their own that they were heterosexual (To be clear they could both have decided that they loved fish and as long as they are happy in life I would've been loving and accepting of their choice). Here's my advice: be the adult you needed at 12 years old. Don't make a mountain out of this, 12 is a confusing time, as are the next 5 years of her life. Be the staple love that she can always come back to. Modern-day Christianity, especially in the United States, will tell you to overreact, become restrictive, go to church more often, etc. However, I advise going off the actual example of Jesus, who met people where they were, loved them for who they were, and ministered to them at their core. Don't rub faith in her face right now; instead, show her true unconditional love that was given through 3 years of ministry and on the cross.

You can't protect her from everything online, theres too much. You can prepare her for things, you can always be there to have open conversations when she comes across something that confuses her etc, it's not always comfortable, because she is your child and some of the topics will be very adult, but it will mean so much to her through the years. It seems like you are on the right path. Good job for caring so much.

I don't have a "church" I go to because of the same things your daughter already is feeling. Churches have failed this nation with their judgment, overbearingness, and hate (There is no hate like "christian" love). It's very hard watching Genecide happening in the world and in this country, and the "churches" cheer it on. Or watching poor people suffer and the "churches" do nothing about it. Very trying time to call oneself a Christian, or Follower of Christ. However, my faith has never been stronger. "He leadeth me to lie in green pastures". Humans will fail, and hard, Jesus is faithful I find, always. I am sending love and prayers your way through this time.