[Zhukov]

Don't build it up to be something dark and important that you have to keep hidden from her. It's not YOUR problem, it's your mum's. I'd mention it, be sheepish and embarrassed and what not, but don't get caught up in saying you are sorry over and over again or asking for forgiveness.

She might still want to meet her. If she does, then, well, you warned her, right?