Scuba,
Inner labia piercings aren't usually the 1st one people think of for added sensation, but as Cloud said, if they are stretched and have a nice little tugging effect. I mean, Idk, I haven't seen Cloud's but 4 gauge is pretty thick, and most girls' inners that I've seen aren't that that thick, and a lot of girls don't want them that thick. Personally, mine are 14g, and I may stretch them up to 10g, but not 4g.
Also, my inner labia are kind of chubby, but they don't protrude lower than my outer labia, so even if I went to 4g, I'm not sure if mine would jingle, unless I added a 2nd ring on each to dangle from the piercings.
Your wife may also enjoy a hood piercing, a VCH (Vertical Clit Hood), or an HCH (Horizontal Clit Hood). Generally, the VCH is more commonly known for sensation, but plenty of girls get added sensation from their HCH depending on the placement and size of the ring. It can be placed so the ball rests on the clit, or hits it frequently, or as one friend of mine says, it acts as a tongue magnet.
I recommend you and your wife look through the hood piercing gallery, and the labia piercing gallery, here on this site together to see what jewelry girls are using and the placements of their piercings. Just go to the blue bar at the top of the screen. I spent about 2 or 3 months looking through pics of girl piercings before I knew what I wanted.
There are also experiences and articles here that you may want to read together. And hopefully more girls will come around with their advice and experience to share with you. I have my inners placed far forward near my clit to keep them from being pulled inside me during intercourse, but with ones as large as Cloud mentioned, I don't think they would be dragged inside.
Take your time, and decide together, and let us know what she gets. Since your profile isn't filled out, I can't tell if you are pierced or not, but if you are and your wife gets pierced, I recommend the article at the top of the General Forum to make sure yours don't get hooked on hers, and cause something to rip. Let us know how it goes.
