A young donkey is call a foal, regardless of gender - same as with horses. Specifically, a young male donkey is a colt and a young female donkey is a filly. An adult male is a jack and an adult female is a jenny.
Typically a baby male or female donkey is called a foal. A foal is usually under 1 year old. Young male donkeys can either be referred to as a 'baby jack' or a male foal. A young female donkey can be referred to as a 'baby jenny (or jennet)' or a female foal.
ubabhemi is a donkey in siNdebele. My second language is siNdebele or isiNdebele or Northern Ndebele. It is a beautiful and expressive language> I don't know what you need the word "donkey" for, but it is "ubabhemi". Salekahle mngan'ami
A female donkey is called a Jenny or jennet, either one can be used. A male donkey is called a Jack or an ass, again either can be used. A baby donkey is called a mule and a child donkey is called a foal, regardless of gender.