[grey_whiskers]

Some folks may have midgit chipmonks running squirrel cages in their craniums. If occasional cortex has anything running in her crainium, it is likely more prone to be gnats farting trying to blow windmills to generate enough electricity to spark a few stray neural synapses that might be wandering through enroute to somewhere else.

The proper phrase as I recall it, is "if brains were gasoline, she wouldn't have enough to drive a piss-ant's motorcycle half-way around the inside of a Froot Loop."

[JockoManning]

Your version is much more economical in words and at least AS vivid in imagined visualization.