Children of Military Service Members Commemorative Lapel Pin Act - Requires a lapel button, to be known as the children of military service members commemorative lapel button, to be designed, as approved by the Secretary of Defense (DOD), to identify and recognize child dependents of members of the Armed Forces who serve on active duty for more than 30 days. Expresses the sense of Congress that the Secretary should expedite the design and manufacture of the button, as well as mechanisms to facilitate its issuance.

Makes such button available retroactively to the child of any member satisfying such eligibility conditions before the enactment of this Act.

Requires the Secretary to notify members with qualifying service since September 11, 2001, of the availability of the button.