This is gonna be scary as hell for you, so take time to think it over. You have to DEAL WITH THIS. The worst thing you can do is try to hide from it.

It was an honest mistake, in a tense situation, with mind altering substances involved. Tell (R) what happened as far as how you were feeling:

(being welcomed into a family unlike anything you experienced growing up, and explain that you just wanted to talk to her mom because you never had a proper parental figure that you could trust growing up. Blame the weed and alcohol a little bit. Honestly it probably did factor in.)

If (R) is as welcoming and open as you describe, she will understand. Just DO NOT add anything more to the pot right now and don’t act impulsively. Don’t open up about crushing on her, just clear up this misunderstanding first and then give her a little time to process.

Equally important, DO NOT hang your self esteem and your feelings of happiness, on your friendship/relationship with this girl. If you want her to be your friend, be a good friend to her. Being a good friend means not putting the other person on a pedestal. She’s a human. She makes mistakes too. She’s still probably going to need space after you explain though, and getting in your own head trying to anticipate how she’s feeling, or trying to pry for more information, will only make things worse.

Tell the truth - take your time typing it out. Don’t send it until you are in a calm state of mind and are happy with the wording. Then wait patiently and let her make the next move.

Hope it works out for you.