My own choices would be :Ana Torent,in Spirit of the Beehive(Erice,Spain,1973), Yella Rottlander,in Alice in the Cities(Wenders,Germany,1974),closely followed by Aida Mohammadkhani,in The White Balloon(Panahi,Iran,1995).All three seem extremely believable,natural and touching.Ivan's Childhood, Ma Vie en Rose, Toto le Heros, Central Station, Fanny and Alexander, My Life as a Dog, Kikujiro and Ponette also come to mind as enjoyable films about children with fine central performances.
What would be your nominations? 