Tania

Tania, alternatively called Anita, is a young hedgehog and the daughter of Brenda and Paulie. Tania has a tomboyish attitude and she is usually seen around her brother, Nicky, and Amy.

In the prose stories written by Kenji Terada, as well as the manga stories written by Hirokazu Hikawa (Shogaku Sannensei, Shogaku Gonensei) and Koichi Tanaka (Bessatsu CoroCoro Comic Special), Nicky's sister is named Tania. However, in the manga stories written by Sango Morimoto, the Katakana in her name is reversed, making her name Anita. The reason for this discrepancy is unknown. Despite the name change, in Sonic the Hedgehog Book's cast page, Morimoto depicts her wearing a shirt with the letter "T" printed on it.

(Source Sonic fandom wikia)