At the start of the term at Charlotte Anderson Elementary School in Arlington, Tex., last year, Stacy Bailey, an art teacher, introduced herself to her new fourth grade students with a slide show of her life.

There were photographs of her family, friends and childhood. There was also one of her partner of seven years, Julie Vazquez, who Ms. Bailey explained was her future wife. They were dressed in fish costumes from the film “Finding Nemo.”

That image set off a sequence of reactions from parents and school district officials that Ms. Bailey, 31, says amount to discrimination, according to a lawsuit filed on Tuesday in federal court in Dallas. She says her career was damaged when she was accused of showing inappropriate images to children, put on leave and told she would be transferred.