Here's a thought...
Don't be an obtuse twat to people who are working for sub-standard wages so they don't have to put up with both a shitty job and you at the same time.
She wouldn't be tapping her fingers if it took you 10 seconds to get your money out. And, yes, not being ready at the drive up window is an asshole thing to do.
Better to lose you then the potential two or three customers that come up behind you and have to wait because you're digging between seats for a dollar worth of pennies.
Well, regardless, having a child for the purpose of filling a void in one's life or initiating a relationship with someone is an invitation to disaster.