If she irrigated the eye thoroughly, and now there is no redness, pain, or vision change in the involved eye, I do not think she needs to see a specialist.
So if her eye is not red or vision change...she doesn't newd to see the doctor rite?
If she was sprayed with AirWick air freshener the Material Safety Data Sheet says to 'immediately remove any contact lenses and flush the eye with water for at least 15 minutes. If irritation persists, see a doctor.'
If her eye is still irritated (red, itchy, swollen, painful) or looks different AT ALL from how it normally appears, I'd get to the eye doctor right away.
Here's a link to the manufacturer's website where you can look up the exact product your sister was sprayed with. Then click on the 'PDF- English' document for the selected product to read what to do about various types of exposure, including being sprayed in the eye:
http://www.rbnainfo.com/productpro/ProductSearch.do?brandId=2&searchType=CAT&template=1
Aerosol air fresheners contain toxic solvents and propellants so they can certainly be harmful to the skin and eyes. Please urge your sister to be careful and seek medical attention if there is ANY change to her eye.