Excessive Potassium

My mother has been prescribed to take Klo-Con M20 tablets. She is elderly and had slight dehydration recently during a bout with diarrhia. After a colonoscopy she experienced rapid swelling of her lower body. She gained 15 lbs of water which she lost in one week upon being prescribed water pills. She has been told by her doctor to stay on one half water pill daily (she has not had any swelling since that first week that she lost the excess water) and one whole potassium pill with it.

My question is, will this lead to excessive potassium levels since she regularly eats food that has potassium in it such as bananas, fresh meat, etc. Should she take a lower dose of potassium pill. The water pill is Furosemide 40 mg tablet by Sando. She takes only half a pill daily.