Trixie was totally minding her own business, certainly not concocting any harebrained schemes to get revenge on Twilight Sparkle. It was totally an accident that Twilight's and Winona's brains were magically switched, and now Winona won't stop following her...
In Twilight Sparkle's body.

They say that revenge is a dish best served cold, but Trixie finds that she has suddenly lost her appetite for it.