I was in Rio with two other older women (in their late 70's) a few years ago and we had no problems. We were careful, but didn't have any trouble walking to restaurants and events in the evening. We used busses and the subway to get around, but didn't dress flashy and were careful when carrying around purses and cameras.

We did get sprayed with some yellow "mustard" when we were shopping downtown, but just ignored the incident and kept walking with purpose. We were able to wash the stains out of our clothing when we arrived back at the hotel.

I've traveled throughout South and Central America with fellow women travelers and have not had any problems. I think if you travel "smart," you won't have difficulity. Besides...I would never give up the experiences I've had traveling to "potentially less than perfectly safe countries."