Grandma searching

Hi I am not sure if Grandmas are allowed to search but I feel there is no one else. My son passed away 2 and 1/2 years ago(he was 24 years old) and it has come to my attention that he had a daughter. I have been contacted by the mother and have been given 2 pictures of the little girl. The mother has told me her parents made her give up the girl or they would kick her out of the house. All I really know is the little girl lives in Texas. I live in Wisconsin and the court proceedings took place in Kenosha. I know here name is Breanna I dont know her birthdate (I know she is 6)and I dont know her last name. I do know my son was paying child support for this little girl. He was married to someone else and was having marital issues with his wife. He seperated from his wife so he was paying child support to both. All I really would like is some contact with the little girl. More pictures some visitation and things like that. Right now she is 6 years old and doesnt know me so I dont even know how to handle that kind of situation. Does a grandmother in this type of situation have any rights? I would appreciate any kind of help