If carrying in a purse (aka: Off Body), the purse strap should be long enough to carry Cross-Shoulder (so it can't simply be grabbed by someone walking by) and the strap should have an internal wire (like a woven fishing leader wire), so the strap can't be cut by a purse snatcher with a box cutter. Having the purse 'snatched' is why Off Body carry is not recommended.

As far as carrying loosely in a purse?? Not recommended, unless the purse has a designated inner pocket, or an area where a holster could be secured by Velcro. Without a holster things could get snagged in the trigger guard, resulting in a negligent discharge (unless carrying without a round in the chamber, in which case, one may as well carry a knife, pepper-spray, or a hammer, instead of a handgun.