Contrary to the summary on IMDb, this episode does NOT introduce us to Brittany's step-mother--she had been in a couple previous ones--including a very early episode where she and Brittany throw a party where, uncharacteristically, Daria is invited.
Of all the episodes of season four, this is among the worst--mostly because it comes off as rather whiny and its view of spirituality is rather superficial and silly. Quinn has a brush with death (or more probably hurt) and decides completely out of the blue that she has a guardian angel. And, through most of the rest of the episode Quinn chalks up every good thing that happens to her as being the result of this angel's intervention. Because Quinn is so popular, soon all the stupid people at school claim to have angels and the idea is definitely trendy. Eventually, bad things also happen--at which point Quinn gives up on the notion and it's never heard about again.
As I said above, this is a very weak episode. Most of it is because spirituality is so trivialized and the show isn't the least bit funny. A rare miss that is, as always, watchable but no more.