bringing a semi-feral cat in?

Has anyone used a catio-type structure to ease the process of bringing a semi-feral cat inside? We have this cat, and she loves to be inside and snuggle with us and sleep in my daughter's bed, but she has a lot of anxiety about not being able to get out when she wants to. We've been in touch with a vet about meds to use. Daughter will likely be moving in a year and a half and bringing cat in would allow her to take her along. Has anyone done this process?