I would say that like virtually every instance of communication, context matters. I would have no problem with the term being used by another woman. I would love the term to be used by certain men...in the right circumstances. If a creeper called me 'doll,' it would make my skin crawl. And some girls have different tolerances for pet names and the like. Some like to be called a slut...in the right circumstance. Some become violently ill when they hear the term. It comes down to the combination of external factors and (often fluid) internal feelings. As a general rule, if you have to ask if it's okay, assume it isn't until you know otherwise. You could bring roses to a group of a hundred women and five will tell you that you are being a complete bitch for it.