Refers to a child who is enrolled in a kindergarten (幼稚園). Often used interchangeably with 幼稚園児, though 幼稚園生 may emphasize the child's status as a student.
See also: 幼稚園児
Our kindergartener enjoys drawing every day.
幼稚園生たちが元気に歌を歌っている。
The kindergarteners are singing songs energetically.