Laura Plummer was arrested in October upon arrival at Hurghada airport after 400 tablets of the opiate painkiller Tramadol were found in her possession.
The case revolves around 290 Tramadol she took with her to Egypt for her lover Omar Caboo, 33, who suffers from back pain, but neither he nor Miss Plummer's family accompanied her in court.
She said "mum, there must be a mistake".
Plummer's trial started in the town of Safaga on Monday with what her lawyers described as a mistaken confession. The family have also denied reports in the media that Caboo has abandoned Plummer for any other wife and/or girlfriend, saying he is "heartbroken" and has stood by her side since day one.
While tramadol is legal in many countries as a prescription painkiller, it is illegal for a private individual to sell it in Egypt, where it is popular among lower-income sectors. "I was anxious about her staying in the police custody; now she will be in the prison with criminal people".
The ordeal has been a hammer blow to the family, who claim Miss Plummer had no idea what she doing was illegal and was just "daft".
Laura's family say she has already suffered vicious beatings at the hands of fellow inmates because she is foreign. Anything less than three years. Her lawyers argue the traveler misunderstood a question in court and gave a response that appeared to be a confession.
"I just can't believe it, she couldn't do three months, now it's three years", Roberta Sinclair, Ms Plummer's mother, told the Telegraph. "Laura did not know that what she was carrying was a narcotic".
According to The Guardian, Britain's foreign secretary Boris Johnson has told Plummer's MP Karl Turner that he will do everything possible to help Plummer and her family. "I think it's a damming indictment about good sense and fair play".
"This is a decent woman who has made a awful mistake who shouldn't be incarcerated in any prison, never mind an Egyptian prison".