Okay, so there's plenty of resonable sounding reasons why it might not be safe, and then again, plenty of resonable sounding evidence that it is.
Here's one thing for definate.....

You can get one as soon as the baby is born.

There's no tattoo emergency is there? You'll still have your skin after the birth (actually, probably lots more skin)

what did you want to get? I was going to get one a few years ago, before I found out I was pregnant with my first- I was going to get a small celtic knot on my lower abdomen, near my hip bone. I'm actually glad I didn't now- well not in that spot anyway, 'cos two pregnancy's later, that spot has probably shifted elsewhere. That little knot would look more like a ball of wool now !!!!!!!!

Use this time to decide exactly what you want, where you want it and the best person to do it- you can never do too much research.

Okay if everybody was to read my statement and stop looking through it and you will see that im telling her its best to wait until after she have the baby to get a tattoo and I know her skin not going anywhere, if anybody want to know if its safe ask your doctor or any professional that do tatoo's too see if its safe or not cause you can't depend on everybody answer.