The question asks to identify the Tirthankara, according to Jain tradition, who is considered a woman.
Tirthankaras are spiritual teachers in Jainism who guide humanity across the cycle of birth and death. There are 24 Tirthankaras in each cosmic cycle.
According to the Svetambara tradition of Jainism, the 19th Tirthankara, Mallinatha, was a woman.
The Digambara tradition, however, holds that all Tirthankaras are male.
Therefore, based on the prevalent Jain tradition (specifically Svetambara), Mallinatha is regarded as a woman.
The Tirthankara regarded as a woman in Jain tradition is Mallinatha.