Planet Inverts says Ghost shrimp do not need brackish water to reproduce. I have had Ghost shrimp for awhile now and always have a prego female. I do not have a ton of babys,but I do have more than I started with and some very small ones too. They are either breeding in my freshwater tank or someone keeps adding small ones.Ghost shrimp larvae require brackish water to survive and become a shrimp. they may hatch but most likely wont survive.
the blackberry shrimp you have are probably some neocaridina species that does reproduce in fresh water. with most species it takes about 3 weeks for the eggs to hatch, depending on tank parameters.
Thats a sweet pick-up, getting all thise baby shrimp for free!
good luck with them all!