If you are only playing against 1 other faction, and all of its children are girls, then your best hope is to find a minor faction (assuming you've turned on minor factions and it hasn't been destroyed - it seems like all the computer major factions like to kill the only minor faction I have ever seen) and hope that they have a son. Otherwise the way elemental is set up, your dynasty will never grow beyond the first generation. If the other kingdom had sons and they got married off to some other faction's children, you should eventually receive notice of children being born/coming of age. As soon as you see a "X has come of age" type message, go talk to the faction that X joined and see if X is male and that faction is willing to marry X into your faction (the notice indicate which side of the family X joined - i.e., 'X grew up but joined Magnar').

You might also be completely out of luck and all factions in game only have surviving daughters.

Given the general aversion to complexity, adoption mechanics are probably far too much to hope for, but I'd certainly enjoy playing with something that had offspring to competed and cooperated according to how they saw themselves in a family hierarchy.

Excluding something like make Janusk a (re-incarnating?) fertile hermaphrodite, it seems like the thing the dynasty system really needs is an option to recruit champions through marriage. That could add an interesting strategic choice between diplomatic marriages and building the family to help produce champions.

And since Rod16 posted that idea, I've been thinking that including champions as viable marriage partners for scions could also support a fix/change to the girls-go/boys-stay thing. Marriage partners should move from weaker houses to stronger houses, unless the stronger house wants to send the offspring away for some interesting reason like a tendency to start riots amongst commoners or plot the deaths of siblings.

Limiting marriageable champions to ones with the Royal trait might or might not help 'good' balance from a math/code POV, but at least a limited option like you describe seems almost obviously necessary now that this thread has made me think about it. I'd rather see computer players able to handle the broadest form of the choice, but I know they're very limited when it comes to planning for the long haul. Letting noble champions marry scions and balancing for CPs by enforcing some sort of ban on 'marrying down' would be better than nothing.

Limiting magic to the dynasty sounds a good idea. Then familly will become important. As far as the fact that you can boost a hero before marriage, you can also boost your own sons. The only differance is that you controll what stats both parrents have. But would that make it overpowerd?

How about a nice 50/50 chance of having a male child.. that would help with the fact that you can never find an AI male to wed. I don't recall the last time I had a male, one in 50 or better I am guessing.

It would be nice if we could see the age of our children.  Knowing how long until they're "grown up" is important.