Sure thing! I'd love to offer Yuuki, but it's just as fine if you all want to do something different outside of her too. I formally offer Yuuki for things knowing she might not be needed. But if she is I'm there!
Also I should have responded to your first comment but well, I'm already here... So in regards to the vampire secret, it's totally cool for him to know! Or if he doesn't specifically know about Yuuki but assumes so because of Zero, that's fine too! Yuuki doesn't really hide it though either since Aidou outed her a life time ago. While she doesn't go out of her way to talk about it, she sometimes casually brings up various aspects of it, too. Like commenting on the smell of something, etc.
ALSO. The short version as to why Yuuki is unusual is because: Pureblood. No one within her family has had children outside of with other pureblood. It's a lot of explaining, but in the end it just comes down to that. The pureblood in canon have 'god-like' powers. I have a thing in my journal that explains a little of the vampire world. It's not much and is mostly drawn from the fan book! I couldn't tell you why the child of a pureblood and human combination wouldn't have poisonous fangs, other than that the power becomes diluted and doesn't become a factor. So out of Yuuki's children in canon, Ai has the ability to change someone else into a vampire because her father is Kaname. But Ren wouldn't be able to, despite being rather strong, because his (I'm assuming ren is a boy still...) father is Zero.