I am a 69 year old woman. In 2015, I walked alone from Avila to Toro, and from Ourense to Santiago de Compostela. In 2017, I walked alone from Ponferrada to Santiago de Compostela on the Camino de Invierno, with an excursion for a retreat at the monastery in Oseira. I also walked for a few days on the Frances with a friend. I did not need anyone to defend me, ever. I do think you need to use common sense and exercise the same precautions that you would anywhere you travel. I met many more people on the Frances than on either of the more solitary routes I took. For that very reason, I felt a greater need to exercise more caution on the Frances than on the other routes. All of my experiences on the Caminos were fabulous, privileged moments of grace and personal development.
One amusing anecdote: in 2015, my husband joined me in Santiago after I finished my solitary walk of about 200 miles. When I offered to run an errand for him, he asked me, "Will you be able to find your way back to the hotel?" The men who love us have a tendency to underestimate our competence, even in the face of strong evidence! I hope this is an expression of their loving concern for us, and not merely male chauvinism....