This is the sort of thing where it helps to get to know the person. In my experience, when I am more familiar with a person, their physical attributes become less important than their personality.

Here is my suggestion:

1. Use your will power to not stare, and treat her as you would treat anyone else. After a 5-6 sessions, you will know what sort of clothing she wears.

2. If she is always wearing clothing that is obviously excessively revealing, and you get used to it, do nothing.

3. If she is always wearing clothing that is obviously excessively revealing, and this distracts you, tell her something simple:

Can I make a request? Can you wear something a little less revealing?

It wont hurt if you blush while you are saying this.

Source:

I was a lifeguard for many years, and enjoyed teaching swim lessons. I taught many adults of every age and gender. One of my students was a physically beautiful woman who wore a tiny bikini. It was so small that it made me uncomfortable. After several lessons, and we had developed a report, at the end of a lesson I asked her if she could switch to a one-piece bathing suit. She blushed for a second and said ok. The next lesson, she had enough coverage that I was much more comfortable. I think the critical thing was that after a few lessons, we had developed sufficient rapport that I didn't come off as critical, but instead just communicating my desire to have a more professional atmosphere.

This is the sort of thing where it helps to get to know the person. In my experience, when I am more familiar with a person, their physical attributes become less important than their personality.

Here is my suggestion:

1. Use your will power to not stare, and treat her as you would treat anyone else. After a 5-6 sessions, you will know what sort of clothing she wears.

2. If she is always wearing clothing that is obviously excessively revealing, and you get used to it, do nothing.

3. If she is always wearing clothing that is obviously excessively revealing, and this distracts you, tell her something simple:

Can I make a request? Can you wear something a little less revealing?

It wont hurt if you blush while you are saying this.

Source:

I was a lifeguard for many years, and enjoyed teaching swim lessons. I taught many adults of every age and gender. One of my students was a physically beautiful woman who wore a tiny bikini. It was so small that it made me uncomfortable. After several lessons, and we had developed a rapport, at the end of the lesson I asked her if she could switch to a one-piece bathing suit. She blushed for a second and said ok. The next lesson, she had enough coverage that I was much more comfortable. I think the important thing was that after a few lessons, we had developed sufficient rapport that I didn't come off as critical, but instead just communicating my desire to have a more professional atmosphere.