Ms Pearce fears she will lose custody of her two young sons
A friend of a British mother convicted of adultery in Dubai has said she is "devastated" after her appeal failed.
Michael Cardy, 43, said 40-year-old Marnie Pearce was "absolutely broken" after a court upheld her conviction.
Her sentence was reduced from six to three months and the court ordered her to be deported. She now fears she will lose custody of her two children.
Amnesty International said that if she were jailed it would consider her a prisoner of conscience.
Mr Cardy, who has lived in Dubai for five years and has two children of his own, told the BBC: "She's broken, absolutely broken.
"She used to be a normal girl, nice, friendly, outgoing, chatty; now she dare not even look at her own shadow. It's horrendous."
He insisted she was innocent and said there was "no way on this earth" she had committed adultery - claims made by her ex-husband, Egyptian national Ihab El-Labban.
Mr Cardy said Ms Pearce needs to raise at least £10,000 to hire a specialist lawyer so she can fight for custody of her children through the UK courts.
Amnesty International's UK director Kate Allen said: "Marnie Pearce maintains that she is innocent, but that is not the only issue at stake here.
"If... adultery charges were being brought to influence a custody battle, it would be deeply worrying. Custody should be a separate, civil matter where the children's best interests come first.
"Criminalising the sex lives of consenting adults is never right, let alone using this to back up family laws which already discriminate against women.
"If Ms Pierce is jailed, Amnesty would consider her a prisoner of conscience who should be released immediately."
Mr Cardy said: "I'm not giving up hope; I won't stop fighting for that girl, I'm disgusted at the way a country can treat women."
"Men can abuse the law here because under Sharia law the man rules the roost."
He also said his friend would look into appealing against the latest verdict on a point of law.