Laura Plummer, from Hull, reportedly entered an incorrect plea and admitted importing the drugs by mistake after questions and responses in court were “lost in translation”.
The 33-year-old shop worker became so upset that the judge was forced to adjourn the hearing, her sister Rachel has said.
It is thought the trial will commence once the defence has found a new interpreter.
The court hearing comes after the tourist was arrested when she was found carrying 320 tramadol tablets in her suitcase. The painkillers are legal in the UK but banned in Egypt.
The woman’s family maintains she was taking the tablets for her Egyptian partner Omar Caboo, who suffers from severe back pain, and described her as “naive”.
They said she did not try to hide the medication and initially thought it was a joke when she was pulled up by officials.
Rachel said: “She’s sleep deprived, she’s visibly nervous and upset.
“She’s answered some questions wrong because she’s not understanding them. She obviously can’t think straight.
“You can imagine the pressure – this is her life.”
She said their mother Roberta Sinclair, who travelled to the country for the hearing, and Mr Caboo were denied access to the hearing as their driver was running late.
Ms Plummer’s lawyer Mohamed Othman said the allegations against his client were “illogical” as her plane ticket was “double the price” of the pills.
He told Sky News: “For someone to be found guilty of drugs smuggling they have to be aware that they are possessing narcotics. Laura did not know that what she was carrying was a narcotic.”
Karl Turner, the MP for Hull East, told Sky News the hearing was adjourned to find Ms Plummer another interpreter.
He said: “Apparently something was lost in translation, the defence lawyer wasn’t confident that Laura was understanding the questions first of all, and the interpreter wasn’t correctly translating what Laura was saying in her answers.”
Mr Turner also praised Foreign Secretary Boris Johnson’s efforts in dealing with the case after Foreign Minister Alastair Burt flew to Egypt to speak to his counterparts.
He added: “The evidence is pretty clear that she didn’t know the drug was banned and she was taking it out there to help her boyfriend, who has come up with the evidence that he does suffer from a severe back problem.”
Mrs Sinclair said her “unrecognisable” daughter was being held in a communal cell with up to 25 women and no beds.
Ms Plummer is being held at the Red Sea resort of Hurghada after being arrested at the airport on 9 October.
Her family has been told she could face up to 25 years in prison or even the death penalty, according to one lawyer.