Sematics or principle or just plain meaness

I am really not sure what my problem is... but here's where I'm coming from today.

Fifteen years ago today - My sister (then 6 months pregnant with her second child) married a man who is leagally still married to her, even though she left him and three children after less than three years of marriage.

Now it's her life... only she can live that life. This I'm good with.

It's the part where she posts on a social network board that 15 years ago she became a wife and mentions till death do us part... yet every year files taxes as single/head of household.

hmmm is it the semantics of became a wife - that floors me the most.... or the part where after having left this family she began... and having said man she married adopt her first born and continue to raise three children as a single dad... she hooked up a time or two with various relationships resulting in another child (who is now 4 1/2) and to me.... that's not a wife.

She now lives with my Dad, unemployed, raising the last munchkin for the most part.

And all I can think is if you don't hold to the action part of the commitment... don't crow about the accumulated years...

So it could be principle... and you know, I'm not beyond thinking... I could just be a mean person and I should forthwith commence praying for my soul because

A) I like the word forthwith (I'm not sure I spelled that right)
B) I should be more open-minded/kind hearted
C) I have no right to judge (this is all too true)
D) Maybe it was better for the kids... she always said it was.

I don't know, but I just had to get that off my chest.

I shall go stand in the corner now and think about what I've said...