Another blood fairy
A blood fairy was an illegal subclass. If one was created, it was the leader's responsibility to get rid of it on sight. If that didn't happen, then the vampires could only assume you were not only going against their wishes, but was plotting something against the vampire settlement.
These subclasses were explained to have a high potential to either be used against them or ruin the current lives the vampires had built up for themselves at the moment.
"Same as Alex, who's Alex?" Silver asked, confused.
Of course, Nate and Leo knew what they were talking about, but Silver didn't. Alex's existence was unknown to her, and she wasn't part of the tenth family. Even if she was Fex's sister, if she found out, there was always the risk she would tell her father or someone else and get them in trouble.