Can it be normal for muscles in non-dominant hand to be smaller than dominant hand?muscle between thumb and pointer slightly less full, but that hand is not used as much! worrisome?no weakness! please respond

Sure: A person's dominant arm and hand should be a little bigger than her other arm and hand, even if the difference is small. The dominant arm and hand does the majority of her activities, so generally ends up with bigger muscles than the other arm and hand. That said, if she frequently uses her non-dominant arm and hand for heavy lifting or heavy work, the non-dominant limb could end up bigger.