(Late comment) I'd forgotten that Joe comes in so early! I remembered the Episcopalian conversion as coming in quite a bit earlier than Betsy's interest in boys. (I haven't read this one in ages and ages, but I can still quote Mr. Ray griping "All that standing up and sitting down, standing up and sitting down...").
And it is so nice that Tacy's stolid disinterest in boys is treated as "Well, that's how Tacy is and why shouldn't she be that way?".