Yeah, I don't know Phil... better I think, considering the stellar performances she's cracked out to date, to conserve all energy till the gun. In fact, probably best just to stretch, and make sure she gets a good position right at the front, then run like the wind. All that active warm-up stuff only has the potential to tire out our heroine, and then she wouldn't get her sub-19 mins would she?
I'm sure you know best D2D. Don't, for goodness sake, get distracted by other people's well-meaning, but non-specific, spoon-feeding advise at this stage.