All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
If this husband pronounced divorce against his wife on two previous occasions, and on the third occasion, he wrote that his wife is divorced with the intention of divorcing her, then his wife is irrevocably divorced and he cannot take her back until she marries another man in a serious marriage and then that man consummates the marriage with her and then he divorces her or dies.
Writing the words of divorce is effectively a metaphor of divorce and divorce is effected if initiated in the form of a metaphor if that was done with the intention of divorce as clarified in Fatwa 87034. Also, refer to Fataawa 82541 and 82583 about the kinds of divorce.
If the family pressured the husband to divorce, then the divorce is still effective unless the pressure reaches the level of coercive compulsion, and the husband's family has no right to request that he divorces his wife if there are no problems in their marriage and the wife is righteous.
For the definition of coercive compulsion, please refer to Fatwa 90215.
Allaah Knows best.