Hi
Sorry I missed your post til now. My husband Bob was diagnosed with type 2 diabetes approximately one year post treatment. As he rapidly gained back the wieght he lost during treatment we suspected that might be the cause or a change in his endocrine system/metabolism due to the radiation. NO Drs have ventured a guess to the cause.

Bob had radiation only and no peg or tube feedings.
As the circumstances are different and I do not recall many others mentioning diabetes after treatment I doubt that Bobs experience has bearing on your daughters. It is an interesting question though and I am curious how often this has been the case.

Sounds like you are doing a good job of staying strong ! Keep on one day at a time.