She obviously has a personal vendetta against vampires, as seen in the first few pages and what she said in the last one. Having a personal trauma that can be related to a "group" (for example hate toward some religion because of some twisted members of it), can easily explain why she hate vampires in general and cases like the teacher who got lied too, reinforce her convictions. While case of "kindness" like seen here, can be perceived as manipulation, since she saw many lose themselves because of that supposed "kindness".
As for how she dodged, simple, Seri announced herself too soon