In February 2010 my sons on\off girlfriend got pregnant we welcomed her into our family and excitedly awaited the birth. My son was at the hospital for the delivery along with his older sister although there was a question of paternity and the mother who was a minor did not put my son on the birth certificate they stayed together and raised this baby as coparents after 2 years and several breakups the mother decided to go after one of the other 2 possible fathers for child support. This man refused without a paternity test which she had refused up until that point the test proved that he was the biological father and he has stepped up to be the dad, the mom still allowed my son to see the baby unless she was mad at him even letting him spend holiday's and birthdays with my family. Now she refuses to let us see or even speak with him on the phone. Do I have any rights as a grandmother or do I need to walk away? My heart is broken but if I have no hope of legal rights I need to know this is affecting my health.

You have no legal rights to the child nor does your son. It's a shame when people choose to use children to play games with other people. All you can do is show support and it's the mother that makes the decision as to what level you receive in return for that support if anything.