Like Dorcas and Mopsa in The Winter's Tale, Audrey is a country bumpkin-ette looking for love. When she's not busy herding goats, she's getting cozy with Touchstone. Audrey's not particularly bright, so it's a bit of a surprise when witty Touchstone declares that he's going to marry her. Whereas Touchstone spends most of his time running linguistic circles around everyone, Audrey has a very hard time with basic vocabulary. As critic Anne Barton points out, poor "Audrey manages to misunderstand the words poetical, features, honest, and foul" the first time she appears on stage.
So what do Audrey and Touchstone have in common? Mutual physical attraction, of course. When they marry, it's clear this couple is not so much in love as they are in lust.