For a 4 year old and between the two, we’d recommend starting with Hey, That’s My Fish for two main reasons. First, the collection of the fish (points) is on every turn and they know immediately how many they get (versus the hidden value on the bottom of the animals in Black Sheep). Second, the game play is simpler in Hey, That’s My Fish and plays quicker – really only one or two things to think about with simple decisions (which penguin to move, which direction, and how far). Whereas with Black Sheep there is more to figure out – which cards to play, how many, where to place them, how they stack up against the others to claim the animals on the field, etc. So we’d suggest starting with Hey, That’s My Fish, then move up to Black Sheep as her ability to handle the decisions develops.