She is a Anodite, like Gwen. Before her appearance in Camp Charmcaster, Ben knew her, but didn't know she had powers. She is 13 years Old, and Since Ben was still 10 Years Old In Camp Charmcaster, she was Older then Ben.
In Ben 10,000 She is part of Ben's team. She now has a Daughter named Lindsey, who has uninhabited her Powers.
In Saga 3 - With Cardcaptor Sakura, Britteny and Ben helped them wipe out Vampire bats made by nickon.
In Ken 10 - The Story of Buzzshock, the girl playing with Ben in a camp is Britteny