This is a difficult problem and there are many facets to it' solution.
Firstly, was the initial diagnosis of CTS correct and was there an improvement of symptoms after surgery?
Yes, there is an association between CPS and type 1 diabetes.
Are her present symptoms due to recurrent CPS.?
If the answer to the above questions indicate that it is a recurrence of compression of the median nerve, then re-exploration and division worth a variety of grafts is the only option.