They are bolt-ons, the way to tell is not if they fall far apart from each other due to gravity, though that is a good clue. A better clue is to see where the nipples are riding. If the nipples are riding up high near the center of the boobs, rather than lower near the bottom of the boobs, then they are fake. Nipples are designed for babies to suck on, from down below, so they evolved to be very low on the boobs. Centralized nipples would only be natural on mother pigs or mother cows or other 4-legged creatures.
Anyways, a girl with a crotch tattoo is no civilian, she's probably a stripper or something. Judged by the standards of a stripper, she's probably only a 75%. Most strippers these days do have tattoos, unfortunately, and she's the epitome of tasteful understatement by those standards; she hasn't gone wild with too many tattoos, but having it on her crotch is pretty wild. But she's only worth 75% on the stripper scale because she's not super-fit, just average fit, and she's not very young either. Unfortunately, those are the harsh realities of the stripper scale.