[Zeke]

She should be able to sterilize her mask in a microwave at work, at home. Other methods some doctors have suggested are:

Heat in an oven for 30 minutes at 158 degrees Fahrenheit (70 degrees Celsius)
Use ultraviolet light for 30 minutes
Soak the mask in 75% ethyl alcohol, then let it dry
Clean the mask with liquid or vapor hydrogen peroxide
Clean the mask with bleach
Steam the mask with hot vapor from boiling water
Microwave the mask (mentioned above but I think it should be damp first, maybe with a small amount of agreeable disinfectant so as to not stink like Lysol)
Soak in soap and water, rinse and dry, (forcibly would be my personal suggestion — hair dryer)

The problem with some of these methods is the likelihood of the mask losing its shape and becoming limp. IDK what a small amount of spray or dip starch would do. YMMV.