What Can Help Relieve Worsening Pollen Allergy Symptoms And Breathing Issues Despite Using Seroflow Inhaler Three Times Daily?

My sister is 32 years of age and is covid negative but she suffers from pollen related allergies every year in April, but this year she is having more breathing difficulties, she has to take seroflow inhaler 3 times a day, still she is uncomfortable. What else can we do to relieve her ?