Without a healer, you're on a strict DPS race to win (made worse if you don't have a Pomander of Lust).

Without a tank, you'd better pray that the person with the highest enmity has a good stock of healing potions.

Just because the gaze mechanic is in earlier floors, doesn't mean people understand how they work (just because you get hit by the Cobra's petrify, doesn't mean you understand why it happened).

She also has this annoying habit of using In Health and In Sickness back-to-back, so as soon as you reach one extreme, you have to run to the other.

I feel like she has a party-wide splash damage attack, but can't really confirm it.

Probably the worst thing to happen is for her to use her "get close" mechanic at the same time the bonus telegraphs show up, since it can leave you with nowhere to stand, because one of those telegraphs covered up the boss.