Grandparent rights

[wingda]

I have a dilema, I have had my grandaughter for 5 months now. Her Mom ( my daughter) left her w/ me and is living w/ another man. My Grandaughter sees her Dad on Sat. till Sunday. I thinks it's time for me to do something. What are my rights? Child Support? Does anyone know what my next steps are? My daughter is living 15 mins away from us & does not visit her girl. The Dad pays most of what I need. They are still legally married.
Please any advice would help,