I think it was mentioned then but she wouldn't expand on it.
I think it was already public knowledge by then as someone had tried to blackmail her about it so rather than give in to blackmail, she went public. Thats my understanding, but I may be wrong.
I think she also had other issues in earlier life such as a messy divorce, and so on, so I may have things mixed up, and she also had a stalker but I think she showed promise as an MP probably because of that experience as a real life person, unlike many in the commons.