In Jain tradition, the answer depends on the sect:

• Śvetāmbara Jains:

Mallinath Bhagwan (Mallīnātha / Malli Devi / Malli Kumari), the 19th Tirthankar, is understood as female in this time‑cycle. She is often called the only female Tirthankar and is used as an example that a woman can attain keval‑jñān and moksha in a female body.

• Digambar Jains:

Mallinath Bhagwan is regarded as male. Digambar doctrine holds that in the present time‑cycle all 24 Tirthankars are male, so they present Mallinath accordingly.

So:

• Śvetāmbara view → Mallinath was female.
• Digambar view → Mallinath was male.

Both agree that Mallinath is the 19th Tirthankar and a fully liberated soul; the difference is only about the gender of the last human birth, not about spiritual greatness.