PRIDE
I am Pride. I disdain to have any parents. I am like to Ovid's flea. I can creep into every corner of a wench. (2.2.110-111)
Aside from this lovely image of a flea creeping into every corner of a wench (pause for gagging), there's something else going on here, too. Did you notice that Pride was first up in this sinful stroll? Pride probably begins the parade of the Seven Deadly Sins because folks thought it was the root of all sin. For example, many believed that at the beginning of creation, the devil fell from heaven because of his pride, because he didn't want God ruling over him. Our hunch is that Pride's refusal to "have any parents" is probably an allusion to that event.
COVETOUSNESS
I am Covetousness, begotten of an old churl in a leather bag; and, might I now obtain my wish, this house, you, and all should turn to gold, that I might lock you safe into my chest. O my sweet gold! (2.3.120-123)
Meet Sin #2, everyone. Covetousness is another word for plain old-fashioned greed, so it makes sense that the embodiment of this sin would want to get its hands on, well, everything. And of course having everything isn't enough; Covetousness wants it all to turn to gold, too. We guess greed only creates more greed.
ENVY
I am Envy, begotten of a chimney-sweeper and an oyster-wife. I cannot read and therefore wish all books burned. I am lean with seeing others eat. O, that there would come a famine over all the world, that all might die and I live alone. (2.3.126-129)
Chim Chim Cheree! We never thought the chimney-sweeper of Mary Poppins was a jealous guy, but maybe we missed… something.