"Okay, this time I'll pretend I'm Lexy using biofeedback to bring the blood to where he wants it to be", and I concentrated on Genevieve and Lexy's love for her and their connection through the blood they shared when they were secretly married, which is how Lexy does that particular Psionic power...
...and they got blood immediately, and I didn't even feel the needle go in, and I always, always, whether they get blood or not feel the needle go in! Which was very cool, regardless of the likelihood that it was pure coincidence.

I tried it again the next time and it totally didn't work.