Lots of ladies with ink will have it removed in their pics as it's often too identifiable for their privacy needs, so it's not always a matter of hiding other aspects of their body or look.
Most good agencies and SPs usually mention that they have tattoos somewhere in the ad or profile though, so you're right to question that.
You could try calling the agency and asking, they'd be crazy not to be straight with you if you made it clear that a heavily tattooed lady showing up at your door would be turned away.
