Love the family member and pray hard, fast and make sacrifices for their conversion. You want them to join you in Heaven, you don’t want to join them in hell.
I am a bit taken back by your comment. You seem to imply that homosexuals are destined for the fires of Hell. Being a homosexual is not a sin as some people still think. It clearly states in the CCC:
2357 Homosexuality refers to relations between men or between women who experience an exclusive or predominant sexual attraction toward persons of the same sex. It has taken a great variety of forms through the centuries and in different cultures. Its psychological genesis remains largely unexplained. Basing itself on Sacred Scripture…tradition has always declared that “homosexual acts are intrisically disorderd.”…under no circumstances can they be approved.
2358 The number of men and women who have deepseated homosexual tendencies is not negligible…They must be accepted with resepct, compassion, and sensitivity. Every sign of unjust discrimination in their regard should be avoided. These persons are called to fulfill God’s will in their lives and if they are Christians, to unite to the sacrifice of the Lord’s Cross the difficulties they may encounter from their condition.
2359 Homosexual persons are called to chastity. By the virtues of self-mastery that teach them inner freedom, at times by the support of disinterested friendship, by prayer and sacramental grace, they can and should gradually and resolutely approach Christian perfection.
Clearly, being gay is not a choice and something that God has made them. Homosexuals just need to lives of chastity, but I would not be at all distraught if my son or daughter were gay. Its at these times that we need to be stronger in faith, and prayer. You shouldnt push your son or daughter away, you should be there to support and help. And there is no way in Hell would I send my son or daughter to one of those “therapy” places to try and “convert” to become heterosexuals. That’s just stupid and doesnt work. Its like putting them through torture and trying to psychologically traumatize them, using shock therapy of genitals and all these horrific things. Mary is a prime example of how mothers should be, love your son or daughter unconditionally!