I'm probably way too late and you've long know this (am on mobile, can't see comments' age), but just answering for anyone who might wonder:
Words in Norwegian can have three genders: Male, female and neuter. Those are not to be confused or conflated with biological gender, inanimate objects can be of either of the three genders, although words for humans that are clearlymale or female generally correspond to that.
The indefinite article for male words is 'en'.
The one for neuter words is 'et'.
The one for female words is either 'ei' or 'en'.
'Jente', as you might have guessed, is female gender, that means it can be either 'ei jente' or 'en jente' - no difference in meaning -, with the latter being a little more common.