Where did this story originate? Is that source reputable?
Here's the BBC's version of it: Kidnapped girl 'rescued' by lions
Sergeant Wondmu Wedaj told the media from Bita Genet, some 560 kilometres (348 miles) south-west of the capital, Addis Ababa, that they found the girl alive but shocked and terrified.
To be honest it doesn't say that the lions deliberately rescued her, but that they chased off her kidnappers.
This reprint of an Associated Press article adds,
The girl, missing for a week, had been taken by seven men who wanted
to force her to marry one of them, said Sgt. Wondimu Wedajo, speaking
by telephone from the provincial capital of Bita Genet, about 350
miles southwest of Addis Ababa.
She was beaten repeatedly before she was found June 9 by police and
relatives on the outskirts of Bita Genet, Wondimu said. She had been
guarded by the lions for about half a day, he said. "They stood guard
until we found her and then they just left her like a gift and went
back into the forest," Wondimu said.
"If the lions had not come to her rescue, then it could have been much
worse. Often these young girls are raped and severely beaten to force
them to accept the marriage," he said. Tilahun Kassa, a local
government official who corroborated Wondimu, said one of the men had
wanted to marry the girl against her wishes.