I'm seeing a few comments in here trying to absolve Eliza of any wrongdoing by placing the blame solely on the MC, but that isn't fair. She's just as guilty as he is. She chose to become a vampire of her own volition. She wasn't forced or tricked into it. She drank from the chalice as fast as she could without doing any research about it, or even waiting to think it over for a few days. She was reckless and irresponsible, and an innocent woman died because of it.
All three of them rushed into this without any sort of a plan for the future, and all three of them should feel remorse for what they have done, and be worried about how much worse it will get. And yet, none of them care about this poor woman at all who died because of their carelessness. Eliza briefly started to spiral into self-loathing, but that was quickly cured with a rooftop hug.
Eliza should be demanding that they lock her up until she can control her urges, but instead she's happily learning to use her new powers, well... right up until she tries to kill her boyfriend because she can't control her urges. But that's okay because he's strong enough to stop her and gives her another hug, which as we saw before is all it takes to convince her that everything is fine.
Everything is not fine. It's totally fucked up. They head back into town to find Dalen, who is researching vampires. He says he's only found bits and pieces so far, and "until we get more information we have to be careful with how we deal with the situation." A little bit late on that one, eh?
"Better late than never" seems to be their approach to research here, but they should've gone with "an ounce of prevention is worth a pound of cure". This whole situation should've been handled with care and caution. Instead, the main cast all turned into brainless incompetent dipshits who created a disaster for no reason at all. There was no need to use the chalice the day they got back.
They should've done their research over a few days before making the big decision, find a source of blood for Eliza to feed off of for the first few days, and then if that wasn't good enough for her, well... at least they tried something. I would've been more sympathetic to them if they tried and failed instead of not trying at all.
This very poorly written part of the game does a lot of damage to the characters, and the story as a whole. It's even worse than the previous story arc about Kira (the pirate who looks and acts like a WVM character), because at least Kira was unimportant enough that we could fast forward through her scenes without missing anything of value. Drinking from the chalice is a huge change to the story, so it can't be glossed over.