What does it mean when you dream of a baby walking?

You're most likely pregnant.

A serious answer:
Although dreams often are triggered by changes in the body's hormones and can reveal a pregnancy, this does not appear to be that type of dream.
> The baby in this dream almost certainly is some project or idea that the dreamer has been developing - just as a pregnant mom "develops" the baby in her womb. Walking represents a significant stage of that development, suggesting that the project/idea is moving toward independence from its creator.