For some, that may be a revolver, for some it might me a .22 target pistol.
I work in a rough part of town and I'm always chatting with lady customers about their best protection....I always advise a light .38/357 or maybe a .44 special...but always a simple lightweight revolver....it ain't rocket science is it?? and you need not be a crack shot.
As for home protection for a single female (or anybody else)...a big loyal territorial male dog is also a must. My 70 year old mom is well served by her 100 lb Dobie...and her lightweight .38/357....she took the course and has had her CCW for 3 years now since my dad passed on.
regards.