Is it OK to be annoyed with someone or am I being judgmental?

You do care about the issue with her clothes....read the first couple paragraphs of your post.

Are you the "leader" of this group? Is there someone to talk to about this?

Is there some type of negative attention seeking going on here? Is this a passive aggressive situation? Are you reading this persons body language & also the people around this person? What type of sentence structure is being used by this person?
What type of reaction is the group giving this person? Where are her eyes during this? What type of tone is used? Is it repetitive? There's so much more here.

It's not a misunderstanding. I'm asking you to step back from the obvious....the clothes...the nails...etc & really "see" the situation from a fresh perspective. Study it. It might even be comical.
Read up on body language, facial expressions, voice inflection etc.
People say a great deal in these areas that most humans don't look at anymore....bec we ignore them. You could have a lot of fun analyzing this situation, but you have to look past the obvious.
FWIW.

I hear that and you do have a point. The day I posted this was after it had just happened and I was stressed out about other stuff so I made a bigger deal over it than I usually do...but yeah.

Ok I can totally understand those annoying things that scratch us the wrong way & get under your skin. Totally!
But I think you could have some fun trying to figure out why this same episode keeps recurring.
You might be surprised by what you find. Could change your whole perspective

Folks, she doesn't have to like this girl. You just can't get along with everyone in the world. There are bound to be people out there that naturally rub you the wrong way. It's a fact of life.

The dislike apparently is based on differences in taste in clothing, and on judging her for the (alleged?) cheating. I think that the concern being expressed here is that OP does not in fact know enough about this person to accurately decide whether or not she can get along with her, or perhaps even like her.

I don't think the taste in clothing is the issue here, more that she tries to hold back the group because she refuses to dress appropriately and then complains about not wanting to get dirty.

If one person is in fact holding back the group, then staff is not doing its job properly.

Rather than automatically judging her, the clothes issue could instead bring out some genuine interest and curiosity as to why she dresses in that manner.

That also is a staff issue. If they aren't handling this situation properly(which they aren't) why should it fall on the op to find a solution? Isn't she there to help her own issues?

I agree that staff should be handling this other person, iPhone has enough to worry about, what with working on getting better and staying better, that I don't feel she should have to worry about this person at all. If she doesn't want to make friends with her, then so be it.

No one stated that this person had to make "friends."

If I am resentful or judgmental on the basis of someone's clothing, then it is my issue.

OP actually has a wonderful opportunity to examine herself and find ways to understand and release the resentment that is being created and/or brought to the surface by this person's clothing and manner.

I know a lot of people just have their style and want to look nice, which is great. I think a possibility for why she feels the need to dress this way everyday+ could be due to low self esteem-maybe she doesn't feel like she looks good enough unless she's dressed to the nines? Not knocking this, I totally understand. Or maybe she just loves the clothes so much she doesn't want to part with them. I know that for me, "dressing up" consists of nice pants (or jeans, depending on how fancy the ocassion actually is) and a clean shirt...so I actually do get it if this is just her style.

Anyway, like I said I appreciate the advice but I'm no longer concerned with this. I was just in a pissy mood the day I started this thread

Thank you so much for your empathetic words about her, and for letting us know that you have moved beyond this.

I am really glad that you brought it up, though, as the thread can stay and be useful to others as well. I know that I have learned from it. Thanks!