I just wanted to get everyone's consensus as to whether I'm being to nitpicky/rude/what-have-you. I just got the save the date card for my brother's wedding next year. It was addressed to Ms. Formal First Name Last Name. Except my legal name is Nickname, not Formal Name. Think Lexy instead of Alexis. I sent a quick email over Facebook to my SIL to be (It had to have come from her, my brother knows my name

) and just said "Hey, got the card, I will. Just wanted to let you know, my name is "Name", not "Formal Name". Just wanted to give you a heads up, see you soon

"
Does that seem ok? I didn't want it to be a big deal, but I also didn't want her to put out invites or anything with my wrong name that our family would see. And I admit, it frustrates me when I get called the wrong name, especially when I've always introduced myself or been introduced by my actual name, and people just make assumptions and call me the wrong name.
What does E-hell think?