In season 3, it is established that Five managed to salvage a neural imprint of Sarah and upload her to a self-contained data node.
But so far, whenever the crew want to talk with her, they have to enter the virtual world of the data node to do so.
In the latest episode I've seen, she mentions while she has complete freedom to redecorate and reprogram the environment as she chooses, she's still just trapped in a room.
Which got me wondering, considering they've established that holograms can be projected anywhere inside the Rasa, especially mobile AI holograms, why don't they just allow Sarah to project herself like this?
She wouldn't have an actual solid presence, but she'd would gain the benefit of social interaction and being able to live as a member of the crew.