My girlfriend often gets sick with anything colds, infections, etc., is there a way for her to boost her inmune system?

Ecchinacea: Herbal treatment such as ecchinacea, goldenseal, ginger tea, zinc may boost the immune system. Hand washing, not inhaling right when someone coughs or sneezes, or not being in the downward trajectory of a cough or sneeze, may also help. However if someone has reoccurring and frequent sinusitis, pneumonia, or bronchitis, then see one's doc as rarely one may have a deficiency in one's immune system.

Not specifically: Not specifically other than the usual exercise, eat a healthy balanced diet, and maybe take a multi vitamin (that includes vitamin d) and even omega 3. If it happens fairly frequently, it may be a sign of an immune issue. Talk to an allergist or even an ent. (feel free to call...Saludo boricua desde texas!).