The issue with that line of thinking, Ryo, is that Alaira doesn't feel particularly vengeful towards Lucilia. To her, 'could have died' doesn't matter to her at all. Since Lyn is safe, she doesn't give a shit. The most she'll do is yell at her a bit. Hell, if she went with someone more violent like, say, Tyrael, Alaira would probably protect her. A lot of this also has something to do with the fact that Lyn likes her. So I'm afraid she wouldn't help.