I have had quite a bit of experience with children birth through five since I have my BS in early childhood education and have been running an early care and education program in my home for the last 12 years. What you're describing here isn't typical. My guess is that something your daughter experienced has caused this change, something that your daughter perceives as a negative and frightening experience. And I say perceived, because at this age, it could be as simple as something she heard people talking about that she didn't understand that is provoking this fear. On the other, it could be something that would be frightening to anyone. Do you know of anything? If not, it would be worth your while to do some investigating to see what's at the bottom of this. If you live in Hanover Township, they have an excellent youth and family services program, which is on a sliding payment scale. I think it would be worth your while to talk to someone there and get their perspective on this.
K.