If I'm not visible there now, I can't be visible there at meetings with her in future. That I wasn't at the execution is excusable, you can come up with some shit about it not being my place to watch vampires kill their own. But if I'm not there at one meeting in your own home and then I'm there at another, the message there is- bad. It will mean you're spooked, and that that's why I'm there.

[ He gives it some thought. ]

Make me visible at first, and then dismiss me when she arrives. As a display of respect. That way I can attend later events if I'm needed and the worst she'll get from it is that she's displeased you somehow.