Seferi began CPR before she was rushed to hospital.
Seymour's heartbroken mum, Julie Felon, has now issued a warning to others not to mix cleaning products.
"I am still in a state of disbelief," she told Surrey Live. "She was only just starting her life and it was taken away from her."
Felon said the cleaning products were bleach and another type of toilet cleaner.
Experts warn that bleach, or products containing bleach, should never be mixed with any other household cleaners as a chemical reaction can release toxic gases.
An inquest into Seymour's death was opened and adjourned on Tuesday, August 4.