Story 1: (spoiler)

good question i must check

have checked: yes she does have a reflection, now goof or intentional.
I would say intentional as she warns about the spate of attacks occuring in the town.
On the other hand how did she become a vampire after dying?

Very good question. She was deffo NOT a vampire when her brother kills her, but we're supposed to believe she was one all along when she turns up for revenge. I think this must have been something they didn't quite think through properly at the script writing stage. Great film though...

My theory is that something in that city or town that transforms people, after death, into vampires. When the detective speak about the city he mentions that there's something wrong there. It's the only explanation possible.
She did not become a vampire until after being murdered by her brother.

I always believe she was a vampire all along (that is, before her brother came to "visit" her). After strangling the man in his apartment, the next scene is the brother in his sister's village in the daytime. He rings her doorbell and nobody answers. Then he goes to the restaurant where he gets the cold shoulder (and we learn that it is nearly evening, getting dark soon) and afterwards he goes back to her apartment where she answers the doorbell.

I never noticed that she cast a reflection in a mirror in her apartment. I did notice that there was no blood when her brother stabbed her several times though.

I didn't think she was warning her brother about "them" so much as acting like she was still human and scared like the other normal people in her village.

I always thought she knew perfectly well what her brother was there to do, and just played along about 'dying' when he stabbed her, for her own (and fellow vampires'!) amusement.

the other townspeople seemed to be aware of the vampires; coexist with them. my theory is that the sister had a vampire roommate (or live-in vampire boyfriend); whom was sleeping when her brother showed up, unannounced. she might have even moved to that town because of a vampire fetish. this vampire was awakened by the struggle between she and her brother. as she lay dying and after the brother departed, the roommate vamped her.

She is most definitely a vampire all along.

She clearly has a leadership position in the vampire clique. That's why the other vampires look to her before deciding what to do about her brother, and then obey her order to dispatch of her brother.

If she had just recently turned into a vampire after her brother attacked her, then her leadership position over the other vampires wouldn't make any sense whatsoever.

Furthermore, her always-was-a-vampire status is corroborated by the fact that she isolated herself from all her relatives and went into hiding - because she didn't want them to find out the truth about her, and/or die to other vampires if they came to visit her.

In addition, her always-was-a-vampire status is also corroborated by the fact that she appeared in the restaurant in the first place. She did not die to her brother's attack because she was already undead, so the attack did not/could not kill her.

If she was a vampire all along, why was she warning her brother about "them"?