The common term for a female bear of any species is SOW
A cub.
Sow
An immature sow
The term 'bear' describes either male or female bears. Infant bears, male or female, are called 'cubs'. Other terms used in English to indicate the sex of an adult bear are 'boar' (male) or 'sow'...
because a female pig is called a sow and a male bear and a male pig are called boars.