...or maybe one will get lucky because she enjoys more the helpless feelings from her prey rather than outright giving any critical step beforehand and it's all pure facade.

That depends on luck,her mood at that time and how the situation spontaneously goes. One does never know unless that you get through it on your own...

Will she have enough mercy this time? There is a chance for that so...she might not be the worst companion to pick but she will surely ensure that you get to deal with a terrifying time. Just like horror games,there are patterns to overcome this. If you get to study her properly,maybe the results will be more satisfying in the /end/ but good luck at figuring them out without shivering first.