Help with a strange anxiety problem that 14 year old just started having

So school's back in and this year my daughter (14) is going into the 9th grade.

This was a big change for her as both her elementary and middle schools were in walking distance where we live. So, we could walk her to school and she could walk back.

The high school is about 6 or so miles away and she has to ride the bus. The first couple days she was very nervous about missing a bus or being left at school. I consider these things normal worries. Things even adults would worry about.

As the week has progressed though, she has shown increased signs of anxiety riding the bus but only in the mornings. Coming back from school she has no anxiety at all.

So, I go into the usual round of questions of is someone bothering you, do you not feel safe, are the kids trying to bully you, etc. She says no. She says she realizes that she has nothing to be anxious over, but she still gets terribly anxious about riding the bus in the morning. She tells me that she cannot eat because of it and she feels really sick to her stomach until the beginning of her first class. After that, her day is fine and she says she is enjoying her classes and teachers and friends. The bus ride back home is absent of any worry.

I do not believe she is hiding anything from me. We have a very good relationship and she comes to me all the time with her problems and issues and we talk it out openly and honestly.

But I am stuck here. I've given her some techniques for dealing with anxiety and all, but this still continues. If it doesn't improve any next week, I guess the best thing to do is to take her to see a counselor.

I really hate seeing her like she is in the morning.

Do you all have any advice for this?

EDIT: Thanks for the replies everyone.

I found out yesterday that it isn't the bus at all causing this. The morning bus produces anticipatory anxiety because when she gets to school she is thrust into 1,000s of kids going to and fro. So, it's really an anxiety of being in a large group of people that's causing this.