Suggest Treatment For Light-headed Feeling And Low BP

My 80 year old mom has been feeling light headed the past three days. She has a fib and takes warfarin every other day and she takes high blood pressure med plus high cholesterol med. she eats very well and walks every day and in the past three days just noticed feeling light headed so she took her blood pressure. Frequently, four to five times a day. BP running 120/70 but has dropped to 109/63. Should we get her to ER or is she good to wait til her cardiologist next month?
She is starting to worry .