I'm sure I don't need to tell you that talking about adoption; you open up a minefield of issues. Read enough about pro adoption or anti adoption and you will find aspects of each that you'll sympathize with.

If you want to adopt you need to know all sides. Adoption is not just one cut and clear case where there is one set of answers. Ideally, babies belong with their natural mothers, and as a society we should be supporting mothers to help them keep their children. Does this mean adoption is wrong? Of course not. In the case of children whose parents are dead, who have no extended family who can care for them, or whose parents are truly unable or unwilling to look after them, adoption is the best solution. Adoption is wrong when the mother or father is coerced into giving up their child either through religious, financial or social pressure.  

A spokeswoman for Save the Children has said that high-profile celebrity adoptions risk sending out the wrong message about adoption. Unscrupulous adoption agencies can benefit financially from high profile cases by luring desperate families to give up their children with promises of providing education and financial support. The adoption industry is worth billions.

Others feel that Madonna is offering an incredible opportunity for Chifundo to have a future she would never have thought possible. They applaud her massive financial donations to children's AIDS charities. The UN says one million Malawian children have lost one or both parents, half of those died because of AIDS. The AIDS crisis affects families to the point where previously children who would have been looked after by their extended families can no longer be successfully cared for. There are millions of orphaned children all over the world who need better care than afforded in orphanages.  

There are of course so many other questions. What is Madonna actually like as a mother? Forget the money, is she loving and nurturing or a narcissistic control freak... (anyone remember Joan Crawford?) 
What sort of life would Chifundo have with her living relatives if they were financially able to support themselves? 

If Madonna is not allowed to adopt Chifundo, how will Chifundo feel in later life about having this chance taken away from her?

What would Chifundo's natural mother have wanted for her daughter? 

I can't tell you what to do. What I can say is that if you want to adopt, you need to find a reputable agency (which in itself can be difficult) If adopting from abroad, consider how you will you maintain a link to the child's cultural heritage. Your sister's opinions are her own. If every human life is worth something does it matter where they come from? Every child in this world is the responsibility of all of us whether they are "here" or "there".