Surprisingly, the bacterial spores they tested leaked noticeable amounts of methane, even after they had been irradiated to death.
But the standards for cleaning the rover before launch are so stringent that there probably won't be enough spores left on the rover by launch time to pose much of a problem.
The most trouble could come from kapton tape, which is ubiquitous and unavoidable on the rover.
When there are limited resources available, simple things like repairing, altering or even making new uniforms could become surprisingly difficult, so Duckworth considers her cosplay experience as something that'll allow her to help out when potential crewmates need help with their clothing.
It is implied that he can't read, though this is contradicted several times.
She then put her cosplay career on hold to pursue another life goal, joining the Air Force and becoming an electrical engineer, but ever since landing the spot in the Mars 100 she's had to shelve that application process and pick up a job with Metlife Auto and Home to pay the bills, all the while resuming cosplay as a hobby.