What makes a parent?

Its a question most of us never need to ponder. Pattys spontaneous offer to help her sister Karen become a mother by donating her ova yields a child they both want to raise but each in her own way. Karen lives alone in what was once a gold miners cabin in Rough and Ready, California, and Patty lives with her husband and their two children in a Sacramento suburb. Patty fears for Dawns safety with her unconventional sister. Karen doesnt want Patty to squelch Dawns vitality. Their unexpected conflict cleaves the family and propels them into an ugly legal battle.

Who should decide? And by what criteria?