Michaella McCollum-Connolly, 20, and Melissa Reid are due to appear in court today accused of attempting to smuggle an estimated e1.7m worth of cocaine out of South America.
Yesterday, her exhausted mother Nora said: “The situation is terrible for everyone.”
The family’s solicitor Peter Madden said they fully support her and are making plans to travel to Peru.
Ms McCollum-Connolly, a photography student and former nightclub hostess, was arrested last week with Melissa Reid, 19, from just outside Glasgow, while trying to board a flight from Lima to Madrid.
The pair claim they were forced to carry bags in their luggage and were unaware they contained drugs.
At the family home in Dungannon, Co Tyrone, Mrs McCollum said her family was going through a difficult ordeal.
She added: “At the moment, we don’t know anything. We don’t know what is happening at all.”
The family’s parish priest, Dean Colum Curry, said they were struggling to come to terms with the plight but were trying to stay positive.
He said: “It is just like a nightmare for them. They are at a loss as to what they can do.
“The family feel almost overwhelmed. They feel intimidated with all the callers to the door and feel a bit like prisoners in their own home. They are afraid to say anything that might jeopardise the situation.
“It is very hard to know who to trust because the system is so corrupt and that makes the situation even more worrying for them.
“But they are still hopeful.”
The National Police of Peru said they found more than 24lb of cocaine — thought to be worth around e1.7m — hidden in food in the luggage of the two women.
Ms Reid’s father William told reporters at his home in Lenzie, East Dunbartonshire, Scotland, that the family are going through a “living nightmare” and have not slept since they found out.
He said his daughter is “bright, beautiful, bubbly, and intelligent, just like her Facebook page shows”.
He said he had a very brief phone conversation with his daughter and told her to be strong and not to get too emotional.
The family are being advised by the British Foreign Office but Mr Reid said they are “not getting much information”. He said there is “no way” his daughter would have gone along willingly with a plan to smuggle drugs.
He feels his daughter may have been “groomed” by somebody who she may have thought was a friend she made on holiday.
The 53-year-old said the family have no plans to go to Peru at the moment and fears going could put his daughter in “greater danger”.