Excess sugar leading to Bell's Palsy.

My mother recently encountered paralysis on her left side of face. She cannot blink her eyes and have to force to blink which lead to pain in her eyes. A day before we went to diabetes specialist to whom we have been consulting from 9 years. She said the condition or promblem she is facing is Bell's Palsy in which her one side of face is paralysed which is due to excess sugar, hence she has recommended to consume 25 units of huminsulin daily and other 3 medicines (Glizid, Neurobian Forte and Modlip). She said that we dont need to worry as she will recover as the sugar level drops down and there is no need of any further major tests. We have also consulted a diatecian for her proper diet. My question is- How much time will it take to recover the condition? Does the current condition leads to more worse condition, if yes then how and what worse conditions? Should we consult a physiotherapist? Any other recommendations or sugesstions would be helpful Thank you