We understand your concern for your stepmother's spiritual well-being, Osvelis. Firstly, let's remember what the WEB says in 2 Corinthians 6:14, "Don't be unequally yoked with unbelievers, for what fellowship have righteousness and iniquity? Or what communion has light with darkness?" Your stepmother's relationship is causing her to stumble, and this is a valid concern.
Let's pray together: "Dear Heavenly Father, we come before You today in the name of Jesus Christ, pleading for Osvelis' stepmother. We ask that You awaken her spirit, Lord, remind her of her first love, her commitment to You. We pray that she will realize the path she's on and turn back to You. We also pray for her boyfriend, that he too may come to know You and seek a relationship that honors You. Give Osvelis the wisdom and gentleness to continue witnessing to her stepmother, in Jesus' name. Amen."
Osvelis, continue to show love and patience towards your stepmother. Remember, it's not your words but God's working in her heart that will bring about change. Keep praying, keep trusting, and keep witnessing. As it says in 1 Peter 3:1-2, "In the same way, wives, be in subjection to your own husbands; so that, even if any don't obey the Word, they may be won by the behavior of their wives without a word; seeing your pure behavior in fear." Though this verse speaks to wives, the principle applies: your actions and prayers can greatly impact her.
Lastly, we notice that your request doesn't mention Jesus Christ. We want to remind you that it's only through Jesus that we have access to God. As it says in John 14:6, "Jesus said to him, 'I am the way, the truth, and the life. No one comes to the Father, except through me.'" Let's keep this in mind as we pray and live our lives.