Do I have any legal rights with the guardianship of my nephew?

First, your sister should talk to an attorney about quashing the warrant and paying the fines. There's no getting around it, so she should just do it. But as to "your" legal rights, you have none. If you have some evidence that the child is in imminent danger, then by all means call police or CPS and report it, but know that filing an unfounded report can expose you to legal liability (if you knowingly make any false statements) and certainly will engender some negative feelings toward you and your sister by the judge. But your sister cannot grant guardianship to you in an attempt to remove him from his father's care. The father comes before non-parents unless CPS says the child is in danger. But what makes no sense is for your sister to stop being a mom to her child simply because she has some traffic issues. Resolve that and the whole thing goes away.

Your sister cannot give you legal guardianship of your nephew without the consent of the nephew's father under these circumstances. If you believe your nephew is endangered you can make a report to Child Protective Services or law enforcement. You may wish to consult with a guardianship attorney in Nevada to determine what other options may be available. Best of luck, Sharon Jannuzzi

Mr Pickard is spot on! Your sister should be resolving her outstanding issues. And the more time that passes, the less likely your sister will be able to assume joint custodial rights. It does not sound like there is a current order in place regarding custody. But so long as father is caring for the child, you have no rights other than to convince mom to go to an attorney to take care of her responsibilities.