I have sailed Mono hulls for many years and almost always solo. However when ever I was making a passage or in a storm many miles from shore I would drag an emergency line. I also had the option to tie off to the rail though. A mono on auto pilot off the coast of California will never stop until the wind shifts or you hit Japan. A cat though is different. Most of my cat sailing is on lakes so falling overboard and having the boat beach its self is just a way to make a new friend with a lake front home
However if I was to take her to open water alone I might take the following precautions.
1 Always wear a PFD no matter how uncomfortable.
2 Tow a drag line I recommend one of substantial length tied to the center of the rear crossbar. Use a small float on the end of the line and a line that floats. Depending on speed it may need to be of considerable length.
3 Have a float plan with someone on shore. Cell phones and VHF are generally useless after about 5 to 10 miles out. Vhf is only good for slightly more than line of site most days.
4 Relax its only a boat and the Russians need Hobies too
What ever you do dont tie your self to the boat. a standard PFD will not automaticly roll an uncounsience person on to their back and the drag of a body knocked out by the boom will with movement most likely drown them before any rescue. Have fun and be safe.