Alif maqsurah is written at the end like an undotted ya: ى. The letter immediately before it carries a fathah. Although its shape resembles an undotted ya, it is read as alif, not as ya. When it is alif of femininity, it is an added letter rather than a root letter.
كُبْرَى: the final sign is ى, and رَ immediately before it has fathah.
ذِكْرَى: the same final shape appears after رَ.
The shape identifies final alif maqsurah. To call it specifically alif of femininity, the word must also be a feminine form; spelling alone is not enough.