Divorce forced by in-laws with false blame of illicit relationship

Female member being blamed by in-laws for telephonic conversations with male friend. Only conversations on phone, nothing in person. But lady blamed to have indulged in illicit relation, but not true, just for applying for divorce. All fake allegations to get rid of the girl from a poor family by a affluent family together. The lady has got twins, one girl and one boy, of age 4 yrs. Husband and in-laws claims for girl baby and if possible for boy also. Notice received for appearing in court on 21 Jun 18. Few voice recordings and messages of the girl with a male family friend, has been taken into the allegations. Girl blamed to have said that she wants to leave the husband & children and go away with the male friend, which is cheap & false accusation. Girl from a BP Line family. Can't afford to take a lawyer. How should she approach the case.