Can i use lidocaine cream on her belly button piercing to ease the discomfort of the new piercing?

Probably not: Lidocaine cream should not be used on broken skin or open wounds, as it can be absorbed too quickly and cause problems with the heart or brain. Try an ice cube on the area for 15 minutes three times a day. Or distraction with a funny movie or a good book. It's safer!

Yes: Triple antibiotic ointment will help as well. Keep a close eye out for infection.

I wouldn't : Placing lidocaine or any cream over a piercing risks the medication entering your system/body. The risks of lidocaine getting into the body could be metal taste in your mouth, tingling/ringing in ears, or even seizure. These types of cream are intended for closed skin. Though a piercing may not seem like open skin, it is.