Tildie's powers manifested when she was asleep in her mother's bed. She was having a nightmare that came to life due to her power. The nightmare killed her mother who was sleeping beside her. Her father rushed in to see what was happening and was also killed as a result. The Cops got calls about the incident and they came to her house to see what was happening. Officer Hoyt was killed in the same way as her parents.
Tildie was then aprehended and taken to Benetech Labs, where she was used a guinea pig for the "Cure" by Kavita Rao. Dr. Rao took pity on Tildie because of her ordeal but really wanted to make a name with her discovery. Tildie then lost her powers as a successful result and stayed at the labs with Dr. Rao as she was now an orphan.
One night, Ord of the Breakworld broke into Benetech Labs. Ord kidnapped Tildie and used her as a hostage hopefully to flush out the X-men. But his plans were thwarted and Tildie was sucessfuly taken by the X-Men and safely returned back to the Benetech Labs.
Tildie had the ability to manifest her own nightmares, meaning she could bring her dreams to life. However, Tildie had no control over this power.
Wolverine and the X-Men
Tildie Soames appears in the episode Battle Lines. She is shown locked up in an indestructible box that was watched over by Kavita Rao. She is freed by one of Magneto's acolytes, The Juggernaut, and he places a device on her neck which makes her use her powers in a wild rampage. Emma Frost while on the Blackbird with Forge have detected that inside the monster was a little girl named Tildie. It was also the same observation of Wolverine. The X-Men encounter her in a comatose state as a monster manifested from her nightmares is attacking the city. Wolverine commanded Rogue to look for other X-Men since they were outnumbered. Instead of following his command, Rogue absorbed the powers of Kitty Pryde and Juggernaut. With the fusion of those powers, she was able to fight the monster and phased through it. She saw Tildie and removed the device. After the device is removed and she is stopped she is take back to the X-Mansion, off-screen, and right at the very end of the episode is seen with some of the other X-Men on the lawn, Tidie is shown playing with Rogue.
She is later seen in the episode Backlash, where she is in the care of the X-men. The X-men go to try and stop Mastermold, and Shadowcat is reluctantly left alone at the school to watch over Tildie. The X-men are unaware that they were fed information to lead them into a trap, during which time the MRD planned to invade the school. Tildie dreamed that the MRD were coming to get her, and while trying to warn Kitty, her powers began to activate. Shadowcat calmed the girl and took her into the room where Xavier is kept when the MRD attacked.