I don't have any info either but my mom told me it was impossible to keep me dressed as a small child. We have a ton of pictures of me at age 2-3, happily playing outside in the dirt, wearing nothing (or maybe wearing undies)
You could google diaper rash, a lot of experts say that giving a child air time helps prevent diaper rash (I know a lot of the cd info on websites says this). Also, we found that being naked helps with potty learning so googling potty training will pop up some interesting stuff. Maybe the Dr Sears website has something?
My boys started out life in cloth diapers and I was using prefolds with a chronic piddler so he was naked a lot to dry out. Now it is a family habit (well, for them anyway and dh isn't that far behind) to be naked when we are home. I love how it teaches them that bodies are different but not to be ashamed of theirs. It has also enabled a lot of talks about what is appropriate touching (my boys are just turned 4 yo and almost 2. About 6 months ago they were playing a game where they were trying to bite each others' penis.
First of all, they are weirdos but secondly, it sparked a discussion about penises being private and if you want to touch a penis, you need to touch your own and leave your brother's alone. Now they say that to me if I touch their penis so it is good. I don't worry much about them letting someone molest them, yk? In fact, I heard ds1 say "Penises are private!" to ds2 just yesterday
Also, I was just thinking, that my children have very sensitive skin and things like tags or seams can really irritate their skin. The bottom line, however, is that this is a choice you have made for your family, a choice you are comfortable with, and your mother can accept it or not but she does need to stop saying bad things about it, especially in front of your dd. You definitely don't want her learning second hand that her body is something to be ashamed of or there is something wrong with her.
Maybe just sitting down with your mother and letting her tell you why she has a problem with it, accepting her view, hearing it. Then tell her your view. Then tell her it is okay to disagree but you don't want to talk about it after this point, and especially don't want her to say anything around your dd.