Congrats on the babies! They are so ridiculously small, that they really won't affect your bioload too much. Yeah, you put her back in th breeder in like 30 days. Remember that she needs to swim sround though to get the drop going, so thats why they often have the fry in the main tank rather than in the breeder. Up to you, I don't put my girls in the breeders anymore because it stresses them and doesn't let them get the excersize they need. However, having the fry in the main tank means more casualties. But, the mom will eat the babies too, and she can pick off quite a few of them will in the breeder with them. Again, all up to you. I have fed mine guppy fry with crushed flakes, first bites, and boiled egg yolk paste. All of those options work well, but I am partial to yolk paste once a day as well as flakes or first bites.
Again, congrats on the new younglings!