Zarina was stabbed on the night of October 23 by the minor and two of her male friends, identified as Abdullah and Shorab, aged 27 years, said a senior police officer.
Police said Zarina is admitted to AIIMS and is out of danger.
"The dispute allegedly originated over Zarina informing her friend Roshini about her (Roshini) husband's illicit affair with the minor. The 15-year-old got to know about Zarina's involvement and roped in two of her friends and attacked Zarina," he added.
He made a PCR call and police intercepted the vehicle on Lala Lajpat Rai Marg, said the officer.
It was later found during interrogation and through a series of calls that they were involved in a case of stabbing and the girl had not been kidnapped, he added.