Alas, looked for Mothers Day stamps or any with just a mother and couldn't find any.
I do really like this stamp which highlights the relationship between Helen Keller and Anne Sullivan.
Anne through her fingertips used words to bring the sights and sounds of the world to her isolated pupil.
They walked through the Alabama countryside, went to Church--Anne became a mother figure, teacher to Helen.
This stamp honors their lifelong friendship, courage and love.
This stamp was first issued on the centennial of Helen Keller's birth.