I want to donate some eggs to my sister, how is it done?

My sister is 35, married, and has been trying for years to get prenent. The problem is she isn't produceing eggs or something I'm not sure I don't really ask because I know it hurts her. I'm 20 and just had an unplanned pregnency. I know it must seem unfair to her because shes the "good" one, shes the married one and she deserves a child. She is so good with my son and I know how much she loves him and it means a lot to me to know shes there for him. I also want her to have a child because I know how amazing it is being a mother and I can't see her go through life with out experiencing it. So what I want to know is if any one knows about how much this will cost and how we get it done. Maybe someone has been through this? Please help us thank you.