Though now a nun, Trinity Butt used to be Jake's high school girlfriend. Actually, it was Trinity's break-up with Jake that lead her to the nunnery - she felt she just couldn't deal with any more relationships or break-ups.
In the years since she joined her convent, Trinity has really perfected the art of wearing her little black habit. In many ways, bringing a sense of style and glamour to her convent has been one Trinity's greatest contributions to convent life (particularly as her spiritual contributions have been somewhat limited).
Trinity appears in A Doyle in the Henhouse.