Next, HOW DO YOU STOP THEM HAVING SO MANY BABIES?!??! I'm at 84 dwarves and 15 of those are babies! That's already almost 1/4. I have a ton of idlers at times, is that why?!
Dwarve women who never see their husbands because both are busy working will still have babies as long as they can path to each other, regardless of their job status. If you ever feel like the population cap is too cheap and unrealistic, you can attempt sex segregation of your fortress as long as you keep in mind that any available path between the sectors breaks the segregation.
Speaking of realism, any civilization with a death rate comparable to the average dwarf fortress needs to produce quite a lot of new people to prevent running its population into the ground. If your fortress doesn't replenish its own population, other forts will have to have even higher ratios of babies to adult dwarves in order to ensure they have migrants to send you instead. And we all know migrants are just babies who eat more and don't have any excuses for not doing anything, so that doesn't make things better, now does it? Granted the game doesn't actually care about overall civ population in terms of sending you migrants -- not yet at least... but it might be more reasonable from the player's standpoint to set an overall cap to limit migration if your fort is successfully producing the next generation, and then give mothers in dangerous professions a maternity leave of sorts like you would in real life, right? (Mind you when I say "more reasonable" I don't necessarily mean easier.)
(Now, if we wanted to be really realistic, we'd discourage excess migration by having a limited supply of rooms to rent -- as they start to run out the price would go up, which would make fewer dwarves want to come... but the game's economy is currently disabled, so that's not an option.)