I would rather have an overweight, kind, loving, compassionate, fair thoughtful grandmother and mother any day over a lying deceitful, abusive, neglectful, hateful mother or grandmother.
As I’ve aged I’ve put on a few pounds compared to my old size for a variety of health and emotional reasons, but that’s life. We can’t change the past, but we can control our future. The world is crying out for good people. Nice people. Loving families. That is something you can control right now, and it sounds like your kids got that from you. Be kinder to yourself. Be patient with yourself, and focus on being “that” grandma. The best one!