The birth of your children will happen during the "time skip" events, which'll advance the time in the game in several steps. However, those events are still far away at the moment, since there is much left to do in the "current" time.
You mean a legendary bow from the raids of the Spire of Courage? You can't craft those.
If you're looking for the bow the elf in the nature raid wants, then you can only get that one from the red chest in the fire raid.
As mentioned, content about the children will not be done until we get to the time skip.