Procedure to file for khula under Muslim Law

Just a few months after her fifth delivery and an altercation her father and I had, my wife started acting erratically, left home with kids to her parents, switched off her mobile and her parents don't allow me in their house. She is demanding Khula. Period. Two kids aged 9 and 8 are living with me for the past one year and the remaining 3 with her. She won't allow maintenance money nor my other 3 kids visiting me, spreads propaganda I don't pay maintenance and threaten me with legal consequences. All attempts for reconciliation have failed. Initially, I thought she is under some kind of post natal psychosis but now after 16 months and her pursuing post-graduation I am not sure what it is. I want to save this marriage, what are my legal options under Muslim Personal Law under Hanafi Jurisprudence? She is decidedly intent on Khula, what are my options to bring home my other 3 kids from time to time while paying for their maintenance, if it ends in Khula?