I don't think you need to make an announcement about attending AlAnon meetings, but if she asks there is no reason to lie either. You're attending for you, not her. I will share that when my BF was still actively drinking, it pissed him off that I went to meetings. He would be in a foul (more foul) mood when I got home from them. So as long as she's not asking, I"d probably suggest you don't volunteer the information.