OK, so I've been playing as the Duchess of Toscana and now I'm Queen of Italy, I have two daughters and one son (I had two more daughters but they died, and my son is a Duke in Spoletto), thing is, both of my daughters has very good stats (the younger one is even a prodigy) and they're about 16-20 years old. Both are currently advisors, but I'd like to marry them to a court-member or someone in my sons court so that they can breed super-advisors (the prodigy-one also got a fertility-event!), but I can't marry them of? Why? I sometimes get marriage offers for them, but it feels like a waste sending them of to live with a courtier on the other side of Europe...