Both of the teenagers who were injured in an unprovoked acid attack in Zanzibar are expected to need skin grafts.
Kirstie Trup has been discharged from London's Chelsea and Westminster Hospital after three days of treatment, while Katie Gee - who sustained more serious injuries - remains there in a "stable" condition.
The Daily Telegraph reported Miss Trup's father, Marc Trup, said his daughter's decision to jump into the sea helped limit the extent of her injuries.
"That completely altered the result, the salt water and the acid," he said. "The other girl panicked, ran around and made her way to a public toilet."
Her mother Rochelle Trup said: "I can confirm that Kirstie has been temporarily discharged until Thursday, when she's back in for a skin graft. We won't make any comments regarding Katie."
Miss Gee's mother Nicky said she did not want to discuss her daughter's condition, saying it was "a very sensitive time", the Daily Telegraph reported. However, it is believed Miss Gee will also require skin grafts because of the extent of her injuries. A spokeswoman for the hospital said earlier they would not release any details on either of the girls' treatment, adding the approach was "in line with the families' wishes".
The pair, who are both 18 and from north London, were on a volunteering holiday on the island, off the coast of Tanzania, when they were targeted. A cleric is reported to be in custody after being arrested on suspicion of carrying out the attack.
The Daily Telegraph said sheikh Issa Ponda Issa handed himself in to police a day after he was injured as he tried to evade officers.
Members of both teenagers' families have been keeping a bedside vigil after the pair were flown home and immediately sent to London's regional burns centre. One friend of the pair told how one of the two men involved in the unprovoked attack "smiled" before throwing acid.
Speaking from Zanzibar, medical student Olivia Moore told Channel 4 News: "The two men were on a moped and they went past a group of tourists. They stopped for the girls and the two men then looked at each other, nodded, and then the man on the back of the bike smiled and threw acid on the girls. Everyone was shocked. Nobody can think of a motivation or anything that precipitated this."