This sounds similar to what I have, but I cannot be exactly sure. However, via my research I have found a lot of helpful information. I apologize in advance if there's any rules against posting links or something like that. If there's anywhere that states these rules I'm not aware and someone would need to let me know. :)
http://www.medicalnewstoday.com/articles/266427.php
This gives a lot of information on anhidrosis and hypohidrosis. There's a section about the tests and procedures near the bottom.
And I would also agree to check medications, although I wouldn't assume she's taking any strong meds.
Best wishes to you and your daughter. If want more details on anything, please don't hesitate to message me. I'm happy to help.
I think you mean hypohidrosis/anhidrosis. Instead of me typing (I suck) all night, go to Wikipedia and type in the above. They will at least give you a list of medications to avoid, Best of luck, jd1963!