TBH I'm not so much good help with working dogs... if she was being introduced into the home as a family dog it would be a bit different. We'd say keep them in separate rooms at night with the older dog where they are used too, but the younger dog would be in a crate or similar in the same room for bed. Crating puppies is a common way of introducing them. Let the older dog have space and be able to "get used" to the pup and when you take the pup out of the crate do it when the older dog is up on the verandah or higher... height and order are important, as long as the older dog walks in somewhere first than the younger dog will learn their place. There is bound to be a bit of telling off. Older dogs don't have much patience with pups and put them in their place very early on. Thats okay, as long as the pups are smart