I d second the thirsties duo wrap recomendation too but as you said it could be the material of the wraps that are irritating her.
I had the Bambino Mio btp set with dd1 and used to find the Velcro scratched her tummy and they leaked a wicked. I still use the prefolds now on dd2 but with the thirsties duo.
I have been finding the last few weeks that she's been getting annoyed with the bulk of them though. She s a similar age to your LO. We have pockets aswell and she seems much happier in those. This thread just reminded me about nippa ing. I might revisit the bikikni fold but and see how i get on.
Are the wraps rubbing between the legs where the bulk is? I usually put the nappy and wrap on and then put my fingers inside the nappy on either side of the crotch IYSWIM and push the middle bit of the nappy towards me making the nappy more narrow between the legs. Does that make sense? I use the boy fold in a wrap so most of the bulk is at the front anyway. I ve also Bern trying the smaller bm prefold with a booster at the front as that is where my dd2 weed most that reduces the bulk between the legs and at the back.
Good luck xxxx