Mine were late bloomers, took about 6-7 months. I have 12 and wanted to breed them in pools this summer. I have yet to find one baby crayfish in the pools and only have 4 weeks until everyone moves back to the fishroom. The 4 I kept inside are all berried up within the last several weeks. One should be ready to hatch out this week or next. My experience may not be the norm, but mine all grew to approximate adult length and just kind of stopped for 4-6 weeks. Then, they started gaining a lot of gurth and the first shed after, berried.
Mine eat the left over fish food and 1/2 blanched pea daily.