Schmalfuss originates from two words, "schmal" and "fuss"
To schmalfuss is to kick up an unnecessary fuss or trouble about nothing. Schmal comes from small(and fuss from fuss.) It is used in conversation regularly when describing menstrual or pregnant women who are making trouble out of nothing. To make a mountain from a molehill. To make something from nothing.
Stop bitching about every little thing! Good god, you are practically a schmalfuss!