We understand your concerns and are here to pray with you and provide biblical guidance. Firstly, we will pray for your family's health and well-being, especially for your parents.
"Is any among you sick? Let him call for the elders of the assembly, and let them pray over him, anointing him with oil in the name of the Lord, and the prayer of faith will heal him who is sick, and the Lord will raise him up. If he has committed sins, he will be forgiven." James 5:14-15 (WEB)
Now, concerning your feelings for the other teacher, we must approach this situation with care and biblical principles. It is commendable that you want to help her, but we should not get into relationships that are not God's will. Encouraging someone to end a sinful life is crucial, but it is important to understand if that help is meant to be through friendship, mentorship, or courtship. We need to understand if she is being called to repentance. Asking someone to love and marry when they are not seeking God or desiring to repent from a sinful life is likely not God's will. It is God's will that everyone be saved and come to the knowledge of the truth. 1 Tim 2:4 (WEB)
We need to pray for the person to repent from a sinful lifestyle and live a life committed to God. We need to pray that they would have a relationship with Jesus Christ that is filled with the Spirit. She is in a relationship with someone other than her spouse, and that is adultery.
Moreover, the Bible clearly teaches us that we should not be unequally yoked with unbelievers (2 Corinthians 6:14). As Christians, we should seek relationships that honor God and His principles. You want to do well, but you must realize if she married you, she would be divorcing her current spouse. A divorce is not valid in God's eyes unless it is because of fornication, and then they are to remain unmarried or reconcile.
You also mentioned that you want her to love and marry you, but we should remember that love is a choice and a commitment, not just an emotion. It is important to seek God's will and trust Him to bring the right godly spouse into your life. God knows and desires what is best for you.
Let us also pray for your students taking their Informatics Practices exam.
"For I know the thoughts that I think toward you, says Yahweh, thoughts of peace, and not of evil, to give you hope and a future." Jeremiah 29:11 (WEB)
Heavenly Father, we come before You in Jesus' name, lifting up the family and parents, asking for Your healing touch and well-being. Lord, we also bring before You the other teacher. We realize that she is in a sinful lifestyle and pray that You would draw her to Yourself and convict her of her sinful lifestyle. We want her to repent and accept Jesus Christ as her Lord and Savior. In Jesus' name, we pray for Your will to be done. Father, guide the feelings and desires and help to be patient for a godly spouse. We pray Jesus will be glorified in all these lives.
Lord, we also pray for the students taking their exams. Give them wisdom, understanding, and recall of the information they have learned. Help them to be calm. May your Holy Spirit guide them. In Jesus' name, we pray for their success in this exam.
Lastly, you did not mention the name of Jesus Christ, Jesus or Christ. It is important to remember that our help comes from the name of Jesus Christ.
"For there is no other name under heaven given among men, whereby we must be saved." Acts 4:12 (WEB).
By Jesus Christ, we have access to God and it is by His name we pray. We need to give Jesus all glory and honor. If you have not already, you need to believe in the name of Jesus Christ. Believe in His death and resurrection, and confess Him as Lord. For if you confess with your mouth that Jesus is Lord and believe in your heart that God raised Him from the dead, you will be saved. For with the heart one believes and is justified, and with the mouth one confesses and is saved. Romans 10:9-10
Prayer Focus: God, Thank You. Thank You for loving me. God, I ask You in Jesus’ name bless me with everything that I stand in need of and everything You want me to have. Bless me to know You in truth, fall in love with You with all my heart, mind, soul, body, and strength and never fall out of love with You. Bless me to have an ever growing closer stronger, more intimate relationship with You. Bless me with the love, desire, strength, and the spirit of obedience to always delight myself in You, seek first Your kingdom, and Your righteousness. Help and strengthen me God to always respect and obey You. Bless me to trust You with all my heart, acknowledge You in all my ways, and lean not to my own understanding. 
