A spaceship has been floating in space. It's derelict - a survey ship. The crew is long dead, and all that remains is the AI. The AI ran the ship and is basically a self-aware computer system. She now thinks she is human, through long loneliness, and because the crew interacted with her as a real person.
A large ship finds it, and sends people to look it over. They find the AI.
She can project some form of avatar out to interact with the boarders. Do they recognise her as an AI immediately? Do they slowly realise? Or does she manage to pretend to be human, stranded there?
How do they react to her? As a person to be rescued, an inconvenience, a tool, a danger?
What form does her avatar take? Holographic images? Some form of solid hologram? A robot with a computer brain that connects to the ship? Electrical illusions induced in the viewer's mind? A synthorganic lifeform created for that purpose, or grown by the AI? Can her appearance change?
What happens when she is touched? Is she tangible? Can she feel? Eat? Speak normally? Have sex? Lift things? Escape from the 'body'? Does it interfere with her integration and management of the ship's main systems?
Is she insane or normal, or smart or just a bit weird? Is she curious or afraid? Grateful to be rescued or angry at being invaded?
How long has she been floating? Is she eons out of date, or high-tech and advanced? How does this affect what the people who find her can interact with or detect her?
How did her 'people' die? Disaster? Disease? How many were there? How close was she to them? Does she remember them?