The berried female [pregnant shrimp are called berried], may or may not give birth. Often when you buy adult shrimp, they do not adapt as well as the young ones do, and females may lose their eggs prematurely. She might have the babies and then die, possibly, too.
If she survives, she can get berried again. Always get immature shrimp if possible, they have a much higher survival rate.
If you plan to raise shrimp, you should know they do best in tanks that are well matured. That means at least a few months old. Adding plants is helpful.
They need biofilm, which takes a few months to grow in enough quantity to suit shrimp. They eat it, and it also seems to provide other services which may not be clearly understood yet. Many fish species also do not do well in tanks that are new for the same reason. No biofilm.
There are not really any good ways to speed up the growth of biofilm, but adding plants, as well as possibly a few leaves, helps as much as anything can. Leaves such as Indian Almond leaf, which has antibacterial properties as well, which are beneficial for sick fish and shrimp, but don't harm filter bacteria. Or some hardwood tree leaves, such as oak or beech; all will grow bacterial colonies that shrimp feed on.
The leaves are left in 'til they turn to skeletons, then replaced with new ones. You can soak them for a bit, or boil for a short time before adding, but you can also just put them in, with a stone to hold them down 'til they are water logged.
Breeding cherry shrimp is not hard, but you do have to meet their minimum needs to get good results. They prefer their water to be fairly hard and alkaline, temps around 70 - 74, they don't do as well in warmer water. Harder water helps with moulting and shell growth. Super hard water can make moulting difficult, and acidic water can also cause issues with their shells.
Feed sparingly, two or three times weekly at most. Many keepers feed only once a week. In a mature tank, that's ok, but in a new tank it would not be ok at all. A feeding dish will help prevent food being scattered, as well as let you see how much they eat. Glass or ceramic is fine. Many use a clean, small clay flower pot saucer.
You should have plants, some hiding places under wood or rocks, or inside shrimp tubes, which are clay tubes made of the same stuff as clay pottery. They look like a stack of tiny clay pipes.
Using tank water or gravel from your angel tank won't help establish the new one any faster. But using media from the filter on the old tank will greatly speed the cycle on the new tank. It can cycle a new filter within days. Then you have to put something in to keep feeding the bacteria in the filter, be it livestock or ammonia, but something, unless you kept that filter on your larger tank for now.
If you keep the new tank filter on the angel tank to maintain the bacteria in it, then you would simply put an airstone in the new tank to keep water circulating while it grows biofilm. Once it has had time to do that, simply take the filter off the big tank and put it on the smaller one and add shrimp the next day or two. Plenty of plants will help keep the water in the new tank pristine too, but so long as it is moving it won't go stagnant.
Of course, if you choose to, you can add shrimp immediately once it is cycled. But be prepared for more deaths and likely no new breeding to speak of, which might be disturbing to deal with.
It is best to wait at least 3 months before you add shrimp.
