Want to see my Grandchild

What is the name of your state? Texas
My stepson is married and they have a child. His wife refuses to let us see the child, however her parents take him all the time, even overnight. We want to be able to see our grandchild and would like to find out any information on filing for granparents visitation rights. My stepson is tooooo weak to stand up to her, so he cannot make it happen...it will take a legal action to change. Any help would be appreciated on our first step. We feel the mother is unfit...she has been diagnosed as manic depressive with psychotic depression and anxiety. She see people that are not there, she is abusive to my stepson. What should our first step be? We are concerned for the child

Unfortunately, there are no "grandparents rights", which many people mistakenly believe. It is ultimately, up to your step-son to make it happen. If she is unfit, why is your step-son still married to her, (depression, psychosis, etc.) I personally would be afraid to leave my spouse alone with the child.