Which of the following is a feminine gender?

Niece:
English Meaning - A daughter of your brother or sister, or a daughter of your husband's or wife's brother or sister.
Bangla Meaning - ভাতিজি। 
- Niece সর্বদা Feminine gender হিসেবে ব্যবহৃত হয়। 

Other options, 
Swan (masculine gender) - রাজহাঁস; মরাল; হংস।
Baby (common gender) - শিশু। 
Dancer (common gender) - নর্তক; নর্তকী; নৃত্যশিল্পী।

Source: 
1. Cambridge Dictionary. 
2. Accessible Dictionary by Bangla Academy.