Becky surveyed the 32 shoppers who spent the most time and money at her boutique last month. Will this result in a representative sample?

I imagine that not everyone that visited Becky’s Store spent a lot of time and money there. If she surveys only those that did, this is not a representative sample because she is leaving out other customers. She would have no one in her sample that represents customers who spent a lot of time but no money, or little time and no money or even little time and a lot of money. These are just some examples but clearly her sample is biased.