@redweasel  
You got darn right! and even her spell Succeed, she will be arrested by Celestia and Luna for this and will reverse the spell, because Twilight is the Crown Princess, NOT Trixie, plus she do not know what is to be a True Princess, Trixie believe is you do all you want but is not, Be Royalty is come big responsibility and is what Twilight do well and she not let her royal statu blind her and rise her ego, Trixie in other hands she will be blind by Pride and is will rise her ego!

@Cheeses  
No is won’t because Trixie do not know use magic as the same level of Twilight and Starlight and even is work, she will be arrested for this, because everypony know Twilight Sparkle is The Princess and she be Crown in centerlot, Celestia and Luna will Punish Trixie for this and is a Crime against the Crown!

The spell worked  

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in which trixie discovers that creating new magic is not as simple as writing down what you want to happen on a scroll

Y’know, This might make a good episode. Some freaky friday shenanigans occur and Trixie swaps places with Twilight.
 
Trixie gets driven to near madness having to put up with Twilights Schedule, Responsibilities and suprising lack of recognition and tries to get a reluctant Twilight (who has enjoyed Trixie’s comparatively easier life) to switch back.

She’s doomed even if it works- that catsuit doesn’t have holes for the wings. Crushing them inside sounds incredibly painful.
 
And that’s assuming nothing goes wrong with the spell or the caster.

Sounds like a solid plan. Nothing can go wrong with that spell.

If you can’t beat em, Cheat em!