live in partner and kids claim of inheritance

My filipino brother just passed away, he was married and have a child with the wife. He then separated after a year of marriage. After that marriage, He met another woman and they live together for over 10 ears. They have 3 children together.Since then, they were separated and met another woman and they live together. They don't have children together. Together, they also bought a house and lot under both of my brother and his live-in partners name. My brother died and the house and lot was not paid for and are still in the process of paying for it monthly. My question is: 1. Does the children with 2nd live in partner has a claim to the house and lot or just the first child whom he married? 2. Can they force the 3rd. live in partner to sell the property to get their share? Need answer to this please....