This is exactly the situation I’m facing - I’m a convert to the Catholic Church who is now discerning religious life and my family members (who are Evangelical Protestants) are not happy about it. What fascinates me is that, as I talk to priests and religious, I have learned that most (if not all) of them faced the same challenge - I have yet to talk to a religious who did not have at least one or two people who were against them pursuing the priesthood or religious life.
It is a hard situation, but one that can be full of grace for all involved. For me, I take comfort in the fact that so many saints faced strong opposition from their families - St. Catherine of Siena, St. Thomas Aquinas… I am also reminded of the apostles who left everything to follow Christ and of what Jesus tells us about discipleship in the Gospel of Matthew: whoever loves their father and mother more than Him is not worthy of Him.
One day when I was really struggling with my discernment and my family’s feelings on the issue, I was led to reflect on the parable of the rich young man (Matthew 19:16-30). You may remember that in this parable, a rich young man approached Jesus and asked what he had to do to gain eternal life. Jesus replied that he needed to follow the ten commandments. The young man responded he did all that, but he seemed to sense something was still missing because he asked what else was needed. Jesus told him to go, sell all his possessions, give them to the poor, and then follow Him. The man went away sad. He was too attached to the things of this world to give them up and follow Jesus. What struck me was what Jesus said at the end of the story - “Everyone who has given up houses or brothers or sisters or father or mother or children or lands for the sake of my name will receive a hundred times more, and will inherit eternal life.”
In dealing with my family, I try to have patience and just live my Catholic faith, trusting that my life will be used by God to witness to my loved ones. I know of one nun who entered religious life against her father’s wishes (he was Buddhist, I think), and she offered up her vocation for his conversion. Many, many years later, she was given permission to be with him at his deathbed, where he did convert.
Bottom line: God’s plans and timing are not the same thing as ours - but we have to be faithful to do what God is calling us to and leave the rest (including our family and friends) in His hands.