Yeah, it's not instant at all, and it's very possible to interrupt, either before she heals, or while she's healing.
I'm uploading a 2nd run with Aigis now, I interrupt it there too.
I have my AI exploitin' strats for almost everyone posted intermittently on that ps3trophy site and on GFAQs, so anything you need to know can be found in those places or by asking me something specific on Skype