We understand that you're facing a challenging situation with your second uncle and the properties he is mismanaging. Let's bring this issue before the Lord in prayer and seek His wisdom and guidance.
Firstly, it is important that all things should be done decently and in order and by the permission and authority of the other shareholders and not by force or manipulation. There is a lot going on here that is deceitful and inappropriate.
Let us pray:
The deceitful are not heartbroken and are not regretful and they do not care that they are deceitful. Therefore it is important to pray for justice and also pray for them as Jesus teaches.
Luke 23:34 - Jesus said, Father, forgive them, for they do not know what they do.
Amos 5:24 But let justice roll on like a river, and righteousness like a never-failing stream
Deuteronomy 32:4 He is the Rock, his work is perfect, for all his ways are justice. A God of faithfulness and without iniquity, just and upright is he
So we pray for your uncle that he comes to his senses and repents from his actions and we pray the other shareholders successfully remove him from his wrongful position. We pray for justice and that any wrongful actions against the law will be exposed and brought to justice and we pray for the protection of the share holders and your mother.
Your mother must stand strong and stand up against any of your uncle's schemes. She should not stand for evil but for good and do everything in her power to make sure the shareholders have the last say. It is important for her to complete her promise of sending a lawyer letter to him and remove him from his position. It may seem harsh but if this is found to be the only solution, it must be done. We pray for the comfort of your mother and she stands her ground and keeps her resolve.
From Psalm 1:1-2, we need to be blessed not to walk in the counsel of the wicked or stand in the way of sinners or sit in the seat of mockers. But his delight is in the law of the LORD, and on his law he meditates day and night
If the girl friend is hurtful we should pray against their relationship.
This is fornication and should not be practiced among Believers, but do not pray against your Uncle, but the problem. This is different than the example of Jesus rebuking and commanding an evil spirit out of a man (Mark 1:25 - Jesus rebuked him, saying, Be quiet, and come out of him!) as in this case we want God to handle the situation and help your uncle come out of this relationship, not harm or dispell the woman. It is important that we pray for her also, but not with her or for their union. We pray not against flesh and blood but against the powers that be.
Colossians 3:5 Put to death therefore what is earthly in you: sexual immorality, uncleanness, passion, evil desire, and covetousness, which is idolatry.
2 Corinthians 6:14 Do not be unequally yoked with unbelievers, for what partnership has righteousness with lawlessness? Or what fellowship has light with darkness?
It is important also to have a relationship with God and focus on putting Him first in all of this and not letting other priorities get in the way of His work.
Matthew 6:33 But seek first God's kingdom and his righteousness; and all these things will be given to you as well.
Furthermore, it is important to note the mention that you did not use Jesus' name or any abbreviation. It is important that while yes praying in the Holy Spirit is encouraged, not everyone understands the language and it is important that we do not fight against flesh and blood. The only way to heaven, is by the name of Jesus Christ, as Jesus taught us to pray in John 14:13 - Whatever you will ask in my name, that will I do, that the Father may be glorified in the Son. Furthermore it is important to have a personal relationship with God through Christ Jesus, our Lord.
John 3:16 - For God so loved the world, that he gave his one and only Son, that whoever believes in him should not perish, but have eternal life.
What this means is that Jesus Christ was born of virgin Mary in Bethlehem, Jesus Christ walked among us and taught the word of God. We are sinners and we all fall short of the glory of God (Romans 3:23) and that the punishment for falling short of the glory of God is death (Romans 6:23) but Jesus Christ died on the cross for our sins so we can have eternal life. Jesus Christ died on the cross and rose three days later. Jesus Christ rose from the grave and sits at the right hand of the Father.
So it is important that we have a personal relationship with Jesus Christ and confess our shortcomings to Jesus Christ and accept his Grace, Love, and mercy in your lives. This is the mission of Jesus Christ, that we confess our sin, put our lives right with God and accept His free gift of grace and then get baptized in the name of Jesus Christ and be born again.
Acts 3:19 Repent therefore, and turn again, that your sins may be blotted out, so that there may come times of refreshing from the presence of the Lord.