Guardianship of My Grandchildren

[suemtrouble]

My Daughter went to Africa to live with her boyfriend who recently married her there. She left her children in my care but didn't leave leagle documentation wtih me to allow me to obtain medical attention and oterh services they were in need of. I obtained an attourney and got Gardianship of the children. Now my daughter wants the husband to come back from africa and take the children to africa with him.I don't believe it is in the best interest of the children to move to Africa. Can I stop them from taking the children out of this country? My Grandson doesn't want to go, Does my grandson have any say so in this situation? He is not the husbands son, The husband is the 2 year old girls dad. I live in indiana. I hope someone can help!