I know this is a personal question but does she remember your mum? Can you explain it to her in a similar fashion. In the end you know your daughter better than any of us, and if you think she's not ready thats totally your call. And you aren't a bad mother if you emelish the truth when you think its in her best interest. I was lucky that Paris did get it, and had she not I may not have done it the way I did. I do believe that all knowledge needs to be relative to age, and maturity (not that I'm saying she's immature but you know how some kids can mature quicker iykwim) and thats only something you can know. Try not to stress about it, I assure you its bothering you way more than its bothering her