By the sound of it you're not going to find out unless she wants to tell you.

Tread carefully and DON'T get cross about it, otherwise you'll never know. Be cool wilth her and see if she'll open up if she knows that you're not going to be mad, but just want to know so you can stop worrying.

Many years ago when I was more foolish and I started 'experimenting' my mum said that she'd never be cross, but wanted me to tell her what I'd taken and what happened so she could understand. Looking back it was a very sensible bit of parenting (for and otherwise very 'straight') mum) and was open and honest about stuff without fear of being yelled at or punished.