BEAT egg white in small bowl with electric mixer on high speed until foamy. Very slowly add 3 tablespoons sugar, beating until soft peaks form.
MIX tapioca, remaining sugar, milk and egg yolk in medium saucepan. Let stand 5 minutes.
COOK on medium heat, stirring constantly, until mixture comes to full boil. Remove from heat.
*Pour 1/4 of tapioca mixture into egg white mixture and gently fold mixtures together so it doesn't lose it's fluffiness. Repeat from * until all of tapioca mixture is folded into the egg white mixture.