I would like to get some feedback on whether or not it is appropriate to invite a friend who I've become close with over the last few months to our wedding next month. When we put together the guest lists and sent out the invitations (on the early end, but everyone has to travel to my hometown so we wanted to give plenty of notice), this friend was more of an acquaintance through my graduate program. Since then we've actually become pretty close, but I don't know whether I should consider inviting her to come to the wedding or not. I've been careful to avoid discussing the wedding with her since she isn't invited as of yet, so she won't be hurt if she isn't invited. If it helps to add more context- we're in a graduate program together, I'm getting married about a 5 hour drive away from where we live (in my hometown), and she will only know one other person at the wedding.
On one hand, I would love to invite her because we've become close. On the other hand, cutting the guest list to a manageable place was painful and we worked really hard to avoid B-listing anyone since I know how rude that is, so I don't want to end up B-listing my new friend. Thoughts?