Talk to General Physician on High Bp Tablets When Bp Is Low

Asalamoalikom. My query is about my mother who is a bp and cholestrol patient. She takes tablets for high bp two times a day as per doctors prescription. My question here is should she take tablets for high bp even when her bp is low? She has been having bp on lower side on the morning for a few days. Shall she notice her bp everytime before taking tablet?