My mom changed her name when she was in her 20s. Nothing drastic, she just combined her first name and her middle name.
She said she regretted that - not sure why, she just said it was a spur of the moment thing. Nobody ever calls her by that anyway - I don't think most people even know about the second half of her name.

Anyway, I like the name Margaret, but McKenzie (that is your first name, right?) is pretty, too.

Sarah

"And death is at your doorstep
And it will steal your innocence
But it will not steal your substance
But you are not alone in this"

“My ability to turn good news into anxiety is rivaled only by my ability to turn anxiety into chin acne.” - Tina Fey