I’m so sorry to hear of the passing of Tetyana Safronova, your dear mother, mother-in-law, & grandmother. I hope that you all can enjoy all the happy memories of times with her now & for years to come - including her explanations of complex Physics!
My deepest sympathy to the family. No words will reduce the sadness of the loss. I hope the memories of аll the time spent together will help. Светлая память Татьяне.