seems rather silly to pump your companies shareprice, and then buy into it ?
if anything, your scenario sounds more like a pump. Wait for you purchases to clear, then shout that you bought ?
personally, I think she should've just bought and said nothing. Traders and investors alike would've eventually noticed her buys when she filled with the SEC.
either way, the CEO buying half a million shares is a good signal to me. She knows more about the future of this company than you or I do.