@rosiecheeks I'm so sorry that happened to you. It sounds like you are very close, so I'm certain that all she would want is to be able to support you. I can understand that having to tell her this is an extremely hard conversation to have.
You have not betrayed her, or yourself. SA is something a lot of people keep to themselves, because sadly it's heavily stigmatised and society isn't supportive of sexual assault victims. It's why so few people report SA to the authorities, or talk about it much. But rest assured that it wasn't your fault, and you didn't deserve it. The only person who has any fault in SA is the perpetrator, no matter what the circumstances were.
If you are worried about talking to her, maybe writing a letter you can give to her would be easier? Then you can take your time finding the words you want to write down. You can choose how much, or how little detail you wish to include. You can say whether or not you want her to ask questions, or what you need from her (just hugs/no hugs, to see a therapist, support in going to the police, if you categorically do NOT want to go to the police, whether or not you want your other parent to know and support you too [if there is another parent in your life], whether you want it kept just between the two of you etc - you can preempt questions you think she may want to ask). She is probably going to find it very upsetting, because she loves you so much.
I don't want to assume your sex or gender at all, but depending on how exactly you were assaulted, please consider having her support you while you get any necessary testing (STD tests, pregnancy tests etc). Some outcomes can have long term consequences if things go untreated/untreated.
Again, I'm so sorry this happened, and please take care of yourself while you deal with the fallout and try to heal.
