Cooter tats don't age well because if the girl gains even just a few pounds, that area above the cooch stretches badly. I've been with a few girls who had tats above their clam that did not look good at all.
Plus if she's had kids, it's going to look awful anyway. Better get a few beers in you before you go exploring below the naval.
This Puerto Rican broad i was dating a few years ago had a tribal "pyramid" tat above her cooch, it covered quite a bit of area. When i first saw it i commented "hey you got some fire on your coochie".

She reminded me it was a tribal pyramid. Didn't look good at all.