How long will it take my female shrimp to hatch its eggs?

I assume you're seeing a ghost shrimp with eggs? The time she holds them depends on things like temperature and various conditions. Once the eggs are obvious, it should be no longer than a few weeks.

cool should i separate her from the big tank???

and how many will i have from 1 shrimp??

What do you have in the tank? Most fish will try to eat the baby ghost shrimp so if you want more babies, put her in a tank by herself with a lot of plants like java moss which harbors the microcritters that the baby shrimp need to eat. It seems that most female ghost shrimp hold 10-20 eggs at once but a huge one might have more.

were do i get java moss and what size do the baby shrimp start off when they're hatched and are ghost shrimp livebarers?
these are the types
of fish in my tank:6-female guppies,3-male guppies,6-neon tetras,2 ghost shrimp,like 4 baby snales.
in my fry tank:4-fryguppies,2-baby snails.
is it possible to put the baby ghost shrimp in with the fry and not get eaten by the fry and will the big ghost shrimp eat the baby guppies????

Ghost shrimp carry eggs under their swimmerettes and then release them. It's not true live birth but maternal care of the eggs under her. The guppies and tetras as well as the parent shrimp will eat babies. The babies are really tiny when born, like 1 mm. I've seen them with my naked eye as small as 2 mm (when checking water I gravel vacuumed out of my tank when I had the ghost shrimp). The baby guppies can easily eat newborn ghost shrimp. Adult ghost shrimp can eat small fish if they can catch them but the babies won't eat baby fish until they are many months old. I wouldn't put your big shrimp with the baby guppies but you could put the shrimp in a net breeder in either tank to keep the baby shrimp contained and safe. As soon as she drops the eggs/babies, remove the mother shrimp. Putting java moss in the tank or net breeder will help a ton because it provides hiding places and food. Most fish stores (local and on-line) sell it with their live plants.

am i able to put the baby shrimp in with the baby fry?