So glad your DH fell in love with your adaptation!
Etiquette-wise, there's no comfortable way to say "hey, this doesn't look right me."
Maybe a brief note to the designer telling her you're a beginner, and that her definition of stockinette as knitting every row confused you because most stitch dictionaries define k every row as garter stitch, and stockinette as alternating k and purl rows. Ask her to change her definition in the pattern from "stockinette stitch" to "pattern stitch" and to put it at the beginning of the pattern so others won't suffer the same fate as you.
All Needful Things
"Knit on, with confidence and hope, through all crises." Except carpal tunnel.
- Elizabeth Zimmermann