Something with a grip, something with a constant fast lens, something with is, something still fairly compact?
I am actually struggling, most of the f2 cameras drop to f5.6 quite quickly when you start zooming..
Theres a panasonic fz200, it's a constant f2.8... Bit bulky tho. G15, not constant, but fast variable max aperture...
Might be an idea to see what cameras have aftermarket add on grips, such as those by Richard Franiec.
Get into a shop, let her have hands on, its probably the only way you'll know whats going to fly for sure.