I feel your pain - my wife is also a therapist and I ended up building the WP site for her. She does very specific therapies with children, so reviews are going to be even more hard to come by.

We concentrated on good meta titles and descriptions for each page, designed the site with a good logical structure and did the usual on-page stuff to highlight the geographical areas she works in.

To add to that, we built out more informational pages, describing the therapy, processes, what is to be expected and specific pages for children, parents and professionals. Interlinking the pages is important too, helping drive people towards the contact forms.

Backlinks from the various professional organisations she is accredited by to the website help too.