Not that I am questioning your authenticity but how does that prove anything? I think you meant to do it the other way around - post something here about what you WILL post on twitter. There's nothing stopping me from posting a message claiming that I am you now and saying "look I posted that tweet before I made this post"
You can look at it either way, however it seems much more unlikely to me that the real Kate might post that and the impostor would be poised ready to take advantage of that. If you look back through my twitter history you will see no similar example of me making authenticity verification posts and the timeline fits in with the discussion on this thread.
Anyway, sorry about slow response!
Edit: you do have a point though I must concede. Herewith another verification code, this time posted here first: DivestKansasNearby1. You'll have to check my @Memset_Kate timeline though since if I edit this again to link in the specific tweet I might have as well have edited it to retrospectively change the code!