Let us first thank Jesus Christ for bringing this concern to light.
We are reminded in Ephesians 4:32, And be kind to one another, tenderhearted, forgiving each other, just as God also in Christ forgave you." It is wonderful to remember old friends and colleagues, but let us be aware of a few principles to have a godly relationship. The relationship should not take away from our relationship with Jesus, but allow us to share the gospel and love of Jesus.
Since Gloria is a woman's name and you have a 20-year history with her, we would not want any previous sins to be repeated nor for her to lead you back into sins that have already been repented of.
Flee sexual immorality. Every sin that a man does is outside the body, but he who commits sexual immorality sins against his own body. Or do you not know that your body is a temple of the Holy Spirit who is in you, whom you have from God, and you are not your own? For you were bought with a price. Therefore glorify God in your body and in your spirit, which are God's. 1 Corinthians 6:18-20 WEB
Let us pray together that you will have godly relationships with all sisters in Christ.
Dear Lord Jesus,
We come before You, lifting up our brother who remembers his colleague Gloria. We pray that their interactions will be godly and pure, bringing glory to Your name. Help him to be a light to Gloria, sharing Your love and truth with her. If there are any past sins, Lord, we ask for Your forgiveness and healing. Guide them both to live in a way that honors You.
We also pray, Lord, that You will bring a godly spouse into his life, someone who loves You and is committed to serving You. Help him to be patient and trust in Your timing.
In Jesus' name, we pray. Amen.
So we encourage you to remember Gloria in your prayers and pursue a godly relationship if she is a believer. If not, pray for opportunities to share the gospel with her. Always remember that our ultimate goal is to glorify God in all our relationships. Let us know how we can further support you in prayer and counsel.