She was exiled and imprisoned by her race, and she reprogrammed the holographic entertainment system on board called Mr White to make the prison her spaceship.
Ruby moves into Sarah Jane's neighbourhood, and uses Mr White to create holographic visual effects and fake saving the day by apparently destroying a crashed meteor with germs inside and helping the gang with defeating a warrior race named the Dark Horde.
Every time Ruby encounters Sarah Jane she weakens her and causes her memories to fail to the point where she is unfit to save the world.
Luke then uses holograms to make meteors visible to everyone on Earth, overloading the capacity of Ruby's ability to absorb emotions, and restoring Sarah Jane's life force to normal.
When Roberts and Hickman could not make the Spiders sequel work either, they then replaced it with Goodbye, Sarah Jane Smith.