I have a couple that I have heard at recent funerals which I thought summed up the mother perfectly. Not sure of your religious views so I am not sure if the first one is appropriate. Second the idea of having someone there to take over if need be, even if they are not needed, its good to have a backup. They're a bit long I'm afraid.
First one
The young mother set her foot on the path of life. "Is this the long way?" she asked. And the guide said: "Yes, and the way is hard. And you will be old before you reach the end of it. But the end will be better than the beginning."
But the young mother was happy, and she would not believe that anything could be better than these years. So she played with her children, and gathered flowers for them along the way, and bathed them in the clear streams; and the sun shone on them, and the young Mother cried, "Nothing will ever be lovelier than this."
Then the night came, and the storm, and the path was dark, and the children shook with fear and cold, and the mother drew them close and covered them with her mantle, and the children said, "Mother, we are not afraid, for you are near, and no harm can come."
And the morning came, and there was a hill ahead, and the children climbed and grew weary, and the mother was weary. But at all times she said to the children," A little patience and we are there." So the children climbed, and when they reached the top they said, "Mother, we would not have done it without you."
And the mother, when she lay down at night looked up at the stars and said "This is a better day than the last, for my children have learned fortitude in the face of hardness. Yesterday I gave them courage. Today, I have given them strength."
And the next day came strange clouds which darkened the earth, clouds of war and hate and evil, and the children groped and stumbled, and the mother said: "Look up. Lift your eyes to the light." And the children looked and saw above the clouds an everlasting glory, and it guided them beyond the darkness. And that night the Mother said, "This is the best day of all, for I have shown my children God."
And the days went on, and the weeks and the months and the years, and the mother grew old and she was little and bent. But her children were tall and strong, and walked with courage. And when the way was rough, they lifted her for she was as light as a feather; and at last they came to a hill, and beyond they could see a shining road and golden gates flung wide. And mother said: "I have reached the end of my journey. And now I know the end is better than the beginning, for my children can walk alone, and their children after them."
And the children said, " You will always walk with us, Mother, even when you have gone through the gates." And they stood and watched her as she went on alone, and the gates closed after her. And they said: "We cannot see her, but she is with us still. A Mother like ours is more than a memory. She is a living presence."
Second one:
A mother is more than a memory. She is a living presence. Your Mother is always with you. She's the whisper of the leaves as you walk down the street, she's the smell of certain foods you remember, flowers you pick and perfume that she wore, she's the cool hand on your brow when you're not feeling well, she's your breath in the air on a cold winters day.
She is the sound of the rain that lulls you to sleep, the colors of a rainbow, she is your birthday morning. Your Mother lives inside your laughter. And she's crystallized in every tear drop.
A mother shows through in every emotion - happiness, sadness, fear, jealousy, love, hate, anger, helplessness, excitement, joy, sorrow - and all the while hoping and praying you will only know the good feelings in life.
She's the place you came from, your first home, and she's the map you follow with every step you take. She's your first love, your first friend, even your first enemy, but nothing on earth can separate you.
Not time, not space - not even death!