To beat February Circus, do this:

The hardest part is the first 4 customers. Do your best to take care of them quickky, but don't pick up the money.

When all 4 customers have left their money on the counter, only take 2 of them and from then on serve 2 customers at a time. Leaving a cake on the display at the end of the round will cause you to lose the round.

IMPORTANT
You do not have to wait for her to finish one task before you click on the next option. As long as there is something to do when she gets to the next option, she will continue to flow smoothly to every command you click, no matter how fast you do them.

Give your impatient customers cupcakes directly before you give them their cakes. Students' meters will fill up completely when they're offered a cupcake.