Hayley Cayton, 34, was found at the house she shared with husband John and three children, an inquest heard.
She was due to go on a romantic getaway to Doncaster on October 6 last year, the inquest into her death in Preston, heard.
She was taken to hospital from her home in Leyland, Lancashire but died the following day.
The court was told that she had suffered mental health problems and depression for a number of years.
Coroner James Newman recorded a narrative verdict and said it was not clear whether she had intended to take her own life or whether she assumed that somebody would reach her in time to save her.