"What--if anything--can keep her from Cat 5 today?"
Eye wall replacement... that's about it.
Shear is low.
http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8shrZ.html
And lowering:
http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8shtZ.html