I wish I could meet your client so I could take her through an assessment to learn all the places where she might have over active and tight muscles which restrict her from being able to touch her toes. Since I can’t do that I will base my answer on what you have told us. I would start by teaching your client to perform self myofascial release using a foam roller on her calves, hamstrings, IT band, and lats. Slowly roll each muscle group over the foam roller to search for the most tender and maybe painful spot. Once the spot is found, hold on that spot for at least 30 seconds. This allows the muscle to relax and release the trigger points. Next, perform a static stretch for the calves, hamstrings, IT band, and lats. Hold each stretch for 30 seconds. Have your client do this 4-7 days per week. If your client can do this routine consistently she will see gradual improvements in her flexibility.