When do you stop chasing vendors?

Our wedding is in 9 months. I've been in contact with a potential vendor for our wedding who is the only one of their kind. We want pie instead of cake for our wedding, and she's the only baker in the area we've found that specializes in catering pie for weddings (or at least, she's the only one that advertises it).



Initial emails were good, I was excited to meet her, and tried setting up a meeting for that week. However, the date I had suggested to meet came around, and I hadn't gotten a response from her.
She replied the next week apologizing for not seeing my email, and suggested we meet this week, and that she'll pick the location. I say that's great, I tell her what day I'm available and wait for her reply. I email her again a few days later to find a good time and place.
Again, today is the day we arranged to meet, but I've heard nothing from her.
I understand a wedding vendor can be extremely busy, but is this is a bad sign? I don't want something to go wrong closer to the day of the wedding and be spinning my wheels trying to get a hold of any of my vendors.
Is it time to move on?