1. I think Allie had antibiotics prescribed because of her chest infection, antibiotics can treat bacterial infections.
2. Brown inhalers when used often can make your mouth/throat dry and sore so she should rinse her mouth with water after using or brush her teeth. She could also use a spacer to reduce this further is possible. There is also a risk of getting oral thrush, following the same preventative measures as above could help this.
3. Washing hands after touching her cat, not rubbing her eyes, taking antihistamines, making sure the house is cleaned and disinfected regularly.