Personally, I'm of the mindset that Owltome+CC automatically invites as much defense as the unit can get. And it's just like you said, running Bold Fighter kinda kinda invalidates the need for speed. It's a slightly different story with mixed phase, since Bold Fighter does nothing on enemy phase, but I think with as much as you've invested in her, her speed should be just fine. TLDR, go with +Def for CC+Owltome purposes. At that point, all she really has to worry about is armor-effective damage and extremely strong green units, I'd think.
Also congrats on the +10!! :D