I was sitting in the new TT for an hour reading the manual. I found it getting difficult to breathe. (with the door open) I went to the restroom in my home, washed my face, and my face was bright red...
have you put vent covers on your TT, so you can leave the vents open all the time. The trailer off-gassing is part of the reason I had them put on before I left the dealer. Even though my TT is almost 2 years old, I try to open it and air it once or twice a month.
My DD is quite sensitive since she was in school and moved into a brand new house. She stayed for a week in my TT while she was visiting and had no issues.