Are your dogs cat-aggressive? You can start introducing them by having a solid wood door, locked, between them. Have someone take the dogs out for a walk, and take the cat inside one of the bedrooms (having windows available for once-outdoor cats is vital to their adjustment). Make sure there's tall furniture or a tall cat tower. Also make sure there's comfortable places to hide in the room. Food, water, and litter all can be in that room and the dogs will learn through your reinforcements that they are not permitted to enter. Eventually the kitty will want to explore the rest of the house (it can take up to 2 weeks for them to come around). When the kitty starts pawing under the door, let the dogs sniff her paws but make sure they aren't mouthy with her. After a few days of smells being integrated, use a baby-gate to allow visual access to each other. Keep the baby gate in place until the cat decides to leave the room on her own. (By now, you're halfway through winter). Then make sure you're monitoring their interactions to avoid injury and stress.