Mother & Child Isles (B2 on the map) are two distinct islands featured in The Legend of Zelda: The Wind Waker for the GameCube. The name is derived from the fact that the two islands, which are so close that they're touching, greatly differ in size. Thus it can be suggested that the larger one is the Mother Isle while the smaller one is the Child Isle. There is only one way to enter these isles, and that is to play the Ballad of Gales on the Wind Waker, which will warp you there. Otherwise you'll just have to marvel at the colossal height of it.
After you complete the Forbidden Woods area, one of the many Korok will plant a withered Deku Tree here. Bring a special type of water found in the Great Deku Tree's area and poor it on it. Another sidequest will have to fetching Blue Chu Jelly after defeating a Blue ChuChu. A Silver Rupee can be obtained by using Treasure Chart #29. One of the three Traveling Merchants will appear on this island after you engage in the Trading Quest. Finally, you can upgrade your arrows to fire and ice arrows by warping here, which will be done by the Fairy Queen.