your guess would really be as good as mine. I also have 2 girls, who are roughly the same age (7+ years old)...but they've never been paired with a male and never laid any clutches. I could be naive, but I'm hoping they get well into their teens.
There is a user named Aliza from a forum I used to visit.... who has her own blog (Gecko Time). She's a great resource.
The Forum is Geckos Unlimited, but I think you have to be REALLY careful who you listen to over there, which is why I think Aliza's blog may be a better place to start.