i'm not sure what you are asking.
your sobriety isn't going to be a big deal to very many other people.
you might as well tell them you've gone vegan.
you seem early in recovery, and bachelorette parties can be pretty dangerous territory...especially if you aren't comfortable STATING you no longer drink and then being disappointed you don't get more enthusiasm from others when you do.
is it NECESSARY to attend?
will the party still happen if you don't attend?
if you were very ill, you wouldn't go.
what are YOUR motives?