How horrible that all those dogs are allowed to run freely. It's sad for all the responsible owners out there who have to worry about their loving pets being hurt or killed.
A cocker can be trained to use pee pads, if that's what she would like to do. It might not be as easy as with a toy breed, and might be a little more messy if it's a larger cocker. Mine is a smaller cocker (about 12 pounds) and she's almost 12 years old. She is trained to go potty outside, but at times if I'm going to be gone all day she will use the potty pad.
As far as exercise goes, a cocker can get plenty of exercise with play in the house. Mine LOVES playing fetch in the house. Your friend could still give the dog additional outside exercise by taking it to a nearby park or somewhere where she doesn't have to worry about dog packs. My cocker doesn't spend much time outside, and she's lived a long, healthy life. I take her on walks around here and at the park, but she never spends time outside alone because we have coyotes and mountain lions around here.
If your friend is set on a cocker, they are wonderful pets. If it will have to be potty pad trained, she might just look and see if she can find a smaller one, because some cockers get pretty big. Mine just happened to be the runt of the litter, but I have seen other little ones before. Good luck!
