Oh she deserves that totally... I've NEVER not cried when she cried. In the scene in Passion where Jenny dies and you see Buffy find out, then Willow, I literally began SOBBING when Aly did. Hadn't shed one tear before that over Jenny, but Aly crying completely broke me. I read somewhere that Joss mentioned that whenever he wanted his viewers to cry, he'd just have Aly turn on the tears. And in his commentary on The Body, he mentions that the scene between Willow and Tara is one of the hardest for him to watch, because he finds it so hard to watch Aly cry.
She's definitely got a way with people's emotions... How I Met Your Mother, American Pie, Buffy... doesn't matter what I'm watching her in. She cries, I cry. One of the most seriously underrated actresses in Hollywood.