One of my friend got married to her uncle at the age of 17 according to their caste rituals but not according to Hindu Rituals with pheras and al.Her marriage was not registered.she only lived for 4 years with her would be out of fear of her parents and society but had 2 children.After that due to misunderstanding and irresponsibility of her husband in giving her love and safety for her and children they were seperated for 15 years and they have no contact.Now she wants to go for second marriage,in this case would she need a divorce?