Graylorne
Archmage
In a fantasy setting, particularly, there are any number of ways around childbearing and suckling issues, bounded only by your imagination and however much reason you want to apply to magic in your world. The idea that those things have to be problematic is too short-sighted, in my view. Of course, you can elect to construct your world in such a way that they are problematic, but it certainly isn't a necessary characteristic of the world. And even without resorting to magic you could address it if you wanted to. As said by BronzeOracle, above, real-world historical limitations are not necessary limitations of your fantasy world.
My Warlocky Kells are matriarchal warrioresses. When young, they have strong urges that help them fight but can be bothersome in peace. To alleviate this, they start practicing sex younger than we do. To prevent accidents, all Kell girls have a small preventive talisman under their skin that gets removed when they've reached a more mature age.
My Shardheld main female character starts adventuring carrying her baby around. No child care in the area. Later, she goes on running and riding while pregnant. Of course those Viking girls were quite hardy...
So I agree it's all quite possible. Just sit down and write it. And study a bit of obstetrics, there's plenty on the internet.