My Coworker Thinks She's Invited to My Wedding

I work in retail and a couple of my colleagues were talking about my wedding planning at lunch, and then one of them suddenly says: "What’s the vibe for your wedding? I’ve been looking online at some dresses that I’ll be buying soon for your big day!" I laughed because I assumed she was joking. She wasn't. Now every few weeks she asks for updates as if she's already on the guest list. We've worked together for two years. We get along well.

But we're coworkers. Not close friends.