If your wife allow Can you pierce her nipples with the sharp needle?

Well considering that you know nothing about body piercing or the anatomical structure of the nipple and areola I would suggest you think about getting her a gift certificate for professionally provided body piercing services. It is very important that you don't mess around with something you know nothing about, infected and botched nipple piercings are not what you have in mind for your wife. Hey nipple piercing are among the coolest piercings out there and the jewellery options are Excellent so do her the biggest favour possible. If she says yes to getting the piercing done then take her to a professional and get them done right, this way both of you can share the experiance and learn about the do's and dont's for the piercings during the healing period. I wont scare you with all the bad stuff that can happen if you try to do the piercings yourself, I think you catch my drift. Do it right and go with a professional!