She'll probably be happy having a room to herself. It'll make her feel secure. If you have a radio, that'll keep her company with classical music. Adult food is fine. When Mattie Grace was at my house (she was a pregnant stray I took in) I fed her dry kitten food and canned kitten food, as she needed all the nutrition she could get. She gave birth to 4 healthy kittens who, along with their mama, all got great homes!!

When your kitty starts giving birth, just observe. Let nature take it's course.