You should tell her. Tell her exactly what it is that she doesn't remember, tell her why. She's in the same position a lot of people here are when they're pulled from different spots in a timeline. There is no sense in treating this any different.
And I know it's hard. I've been there with Betty. Carol Danvers lost a lot of her memory because of what happened to her. And well, Tony Stark used to have a lot of blackouts, and a lot of what happened during them ended up being pretty personal for me. None of this is the same just -- if she's asking the questions, they deserve to be answered.