Dawn (game)

Dawn is the female player character in Pokémon Diamond and Pearl as well as Pokémon Platinum.

If the player chooses Lucas, the male player character, Dawn will be Professor Rowan's assistant. She helps the player by teaching them about important elements in the game, such as item shops and Pokémon Centers, how to catch Pokémon, and also gives items during the adventure. She is also part of the Pokédex project. The other blond haired rival will fight you throughout the game, but Lucas/Dawn (depending on the choice of being a boy or a girl) will only assist you politely.

Pokémon Diamond, Pearl & Platinum
In Pokémon Diamond & Pearl & Pokémon Platinum, you will befriend others, such as the champion, and people you tag team with, like Barry, before and after you beat the game. Dawn will always be in possession of the other starter that wasn't chosen, the one which the player's starter will have an advantage against. i.e. if the player has chosen Chimchar, she will have a Turtwig in her arsenal. The reason being that if the player character is Lucas, you won't battle her at any point because she has the Starter Pokémon with a type disadvantage to his own. Similarly, if the player character is Dawn, Lucas will choose the disadvantaged starter.

Trivia

 * Dawn's outfit in Platinum is the same outfit Dawn wore in the anime when she, Ash and Brock visited Snowpoint City.
 * However, she kept her gold barrettes instead of her pink ones.
 * When you first beat Cynthia in Pokémon Black and White, she mentions either Lucas or Dawn. Referring to him/her as "That trainer who faced Giratina", she then admits she was rambling about things that didn't concern the current player.
 * In Diamond, Pearl, and Platinum, Dawn has an unnamed father that works at Professor Rowan's lab.