If it's the one I'm thinking of, it's called 'Song for a Fifth Child' by Ruth Hulburt Hamilton
Mother, oh Mother, come shake out your cloth,
Empty the dustpan, poison the moth,
Hang out the washing and butter the bread,
Sew on a button and make up a bed.
Where is the mother whose house is so shocking?
She�s up in the nursery, blissfully rocking.
Oh, I�ve grown shiftless as Little Boy Blue
(Lullaby, rockaby, lullaby loo).
Dishes are waiting and bills are past due
(Pat-a-cake, darling, and peek, peekaboo).
The shopping�s not done and there�s nothing for stew
And out in the yard there�s a hullabaloo
But I�m playing Kanga and this is my Roo.
Look! Aren�t her eyes the most wonderful hue?
(Lullaby, rockaby, lullaby loo).
The cleaning and scrubbing will wait till tomorrow,
For children grow up, as I�ve learned to my sorrow.
So quiet down, cobwebs. Dust go to sleep.
I�m rocking my baby and babies don�t keep.