Time Management and FF:
If you are getting chicks you will need a few minutes to feed and water them every day regardless of which kind of feeding you do, and as others, I have found once you get through the first few days of adjustment (starting on a Saturday decreases the impact of this and you can time yourself) FF takes no more time than dry, and in many ways less, because I make fewer trips to the feed mill. Turkeys can also eat FF.
Preteens can be really good at helping, and presumably at least one or two of the pets are his/hers, so feeding and cleaning them should be the preteen's responsibility - I was a single mom too, like Bee, completely understand how difficult it is to manage time, and unless the preteen wants to pitch in on pet care, you may have too many animals. I got into that situation myself, and had to cut back, which broke my heart at the time, but it was the right decision for me and my son, and for the animals. They had more attention from people who had more time for them, and I finally got some rest and had a better attitude toward my son. I figured he was only going to be growing up once, and that had to be at the top of my priority list.
Once I realized I was actually only one very imperfect human being who only had so many hours and so much energy in each day, and adjusted to my new reality, life got a lot more manageable.