There is no specific reference in Irish folklore to there being female leprechauns. However, the word leprechaun itself, which dates from around the turn of the 17th century, is not gender-specific. It derives from the Irish word "lupracan" and the Old Irish word "luchorpan," which simply means "a very small body."
Without female leprechauns, the question arises as to how folklorists suppose leprechaun populations are maintained. In answer to this question, some experts have suggested that they do not procreate at all. Rather, the leprechauns are the malformed and bad-tempered children of fairies.
This theory is not universally accepted, however. The conservation area known as The Silabh Foy Loop in Carlingford, County Louth boasts a rich folkloric heritage and attracts tourists with legends of leprechauns. Following their successful campaign to protect the area under an EU directive, locals hinted at the implications for leprechaun populations. One man told the IrishCentral website that "our little people will be protected from extinction and allowed to thrive on the mountains." This suggests that leprechauns are believed to procreate, at least according to some people, and that there must therefore be female leprechauns. In any case, given the lack of specific references to female leprechauns in Irish folklore, it is fair to assume that they have no special name to differentiate them from males.