I think neon green and yellow stand out more than pink in the daytime (whereas at night/when lights are on reflectives are more important). Showers Pass offer this neon waterproof jacket which also has some reflective fabric.
I would also suggest looking at women's professional team kits (although the choice and availability to purchase is nowhere near as good as the men's). The pro team strips are designed to be eye catching, because they are advertising. Very often the most eye catching kits are also the most hideous/tasteless, which is no bad thing: if it looks so awful that drivers can't help noticing it and thinking it looks awful, then that means they have registered the presence of the cyclist.
She might also like to consider getting a mirror. SJS Cycles have a good range here, and I particularly like the B&M mirror for drop bars, given that it is often more awkward to look over your shoulder when using drop bars as opposed to flat bars.