Feminine gender of 'stallion' is-

Feminine gender of 'Stallion' is - গ) Mare.

• Stallion (ঘোটক/ঘোড়া)
- English Meaning: a fully grown male horse, especially one that is used for breeding.
- Feminine gender: Mare (ঘোটকী; মাদি ঘোড়া)।

• Other options:
Heifer (বকনা বাছুর)
- English Meaning: a young female cow.
- Masculine gender: Bullock (এঁড়ে বাছুর)।

Horse (ঘোটক/ঘোড়া)
- English Meaning: a large animal with four legs that people ride on or use for carrying things or pulling vehicles.
- Feminine gender: Mare (ঘোটকী; মাদি ঘোড়া)।

Knight (বীরযোদ্ধা)
- a man of high social rank who had a duty to fight for his king.

Source:
1. Oxford Learners Dictionaries.
2. Cambridge Dictionary.