I want to get married!

[Jamers]

Wow. You are really into this game.

For a mage, I'd recommend getting Feanora, the Frog (princess?) from Marshan Swamp. That is, if you didn't bag her and hand her over to the Duke or the Earl or whatever in Arlania.
If instead you chose to get the potion for him and free her sisters, you can wed her, and she gives +3 intellect in her human form and +100% attack for snakes and spiders in her frog form (not nearly as useful unless you're leading an army with a couple troops of snakes and spiders, obviously.)
Also, her slots are 2 artifact, 1 artifact / belt and 1 helmet. Artifacts tend to benefit mages, and I've found both belts and helmets that do as well, so she is definitely a solid choice for a mage.

Know that having children is risky--you don't know which child you're getting (drawn from a pool at random, like everything else in the game) until 10 battles after you talk about it (conceive). Children are risky. Some are really beneficial (my first child on first play through gave +5 intellect), and some are crap (+4 scroll capacity). I'd probably recommend not having children so that you have more control, but it's up to you.

Hope this helps.