Does anybody know anything about step parents rights? Do we have any? Where do I look to find out more?

As far as I know, for Maryland anyway, the answer is yes and no. My husband is a stepdad to my son, and before we were married I inquired about this same thing. I was told by an attorney that in the case of death of the custodial parent, the step parent has the right to fight for custody if of course they can prove the other parent unfit and/or there is no other family fighting for custody.
When it comes to everyday life of a minor child, who lives in the home, the step parent is viewed as a guardian. For example, school, doctor office, emergency room etc...
In my experiences, it's never come up. It really isn't anyone's biz, you know. I hope all is well for you and your family. I hope I gave you some insight.
Happy Holidays! j25has