They are small plastic or metal tubes placed in the ear drum that allow equalization of pressure and any fluid to drain out. For adults they can be placed in the clinic.
There are a few things she can try at home. 1) have her plug her nose and blow and/or plug her nose and swallow to see if that opens the Eustachian Tube. 2) Take an OTC antihistamine & decongestant. 3) She could also try a NeilMed Eustachi or similar device that is supposed to help open the Eustachian Tube to relieve the pressure.