You've actually disproven your claim.

> The paygap is just a measure of the number of women having children.

> A woman who has two children, at minimum, works two years less. In a (25 - 65) yr career that's a 10% pay gap she'll experience wrt a male who works the same period.

Your claims are disproven by your own math.

A paygap over that period would be a 3% to 8% drop due to child rearing, not 10%, if we accept your claims.

In reality, in the US women do not usually take 1 year off per child. Paid maternity leave is 12 weeks by federal law. That creates a "motherhood-caused" paygap of only 0.75% to 2%.