What are a young father's rights in Texas?

My little brother is 18 and his girlfriend is 17yrs. old. He got her pregnant while living in Houston. Since the beginning of the pregnancy our family was supportive and wanted to be a part of the baby's life. The girls mom on the other hand has kept my brother and us away from the baby. During her pregnancy they moved to El Paso. My brother is on the right track and graduated school and is enrolling in college soon. He also has a job and is looking for a full time higher paying job. The girl on the other hand doesn't. She lives with her mom, who is unemployed and lives with her sister and other family members. The baby and the girl sleep in a closet. The girl is very immature and posts pics of herself half naked and admits online to doing drugs and even considered suicide while pregnant. The mom does not allow my brother to call and speak with the girl to check up on the baby and instead is constantly asking for money. My brother instead sends what the baby needs. He has asked the girl to marry him im hopes she will move back to Houston but she says she can't. My brother was allowed to see the baby when she was born but only when her mom said it was ok. My brother did attempt to move to El Paso to be closer to his daughter but was unable to secure a job, place to stay or transportation. Reluctantly moving back to Houston where he has all the support of his family. We want to know want he can do to have more rights and make sure his daughter is safe and not sleeping in a closet. Does he have a chance? The girl turns 18 in May but there is fear the girl and mom might up and leave before then. What can he do as we don't have a lot of money for legal fees and attorneys. Thanks for any help and info.