Shepard, male or female, isn’t in this game. In Mass Effect Andromeda you’ll become one of the Ryder twins.
Which you take on is completely up to you. Both Scott and Sarah are customizable, though we’re waiting to see just how much about them players can really change. Also customizable is the Pathfinder himself, their dad Alec Ryder. When you change the look of Scott or Sarah, you change Alec’s features too.
Choosing Scott or Sarah doesn’t mean that the other is gone. The character that you don’t choose will still heavily feature in the game, Bioware has confirmed. Players will get the option to customize the moves of Scott or Sara, just as they’ve done in previous games. Early rumors indicated that players would be limited to three abilities, but that’s since been debunked.