Helloo! 8D I do believe I have bought a few wigs from you y/y?
I'll try and help you out a wee bit if that's okay!
Avatar 1!
I feel like the pants layering makes this look a little bare, and almost like you're not wearing pants? Maybe one of the flirty skirts would have went well here! The black one perchance? Just a suggestion. I feel the face is a little bare too, I say it all the time here but faces really can make or break an avatar, you could have the nicest avatar ever but if it's got a bad face, it's not gonna work.
Avatar 2!
I love the idea behind this, matching the companion is an adorable idea, but the items don't really work with one another except colour-wise. The mix of old and new art is a little off-putting, so it's always good to be careful of mixing items that aren't all that similar! Other than that I like this though

Avatar 3!
This is my favourite of the 5, I think the colours are cute and the face is a little more expressive than the other avatars you've posted. It is a little simple though, which isn't a bad thing but sometimes you have to find that balance between too little/too much, y'know?
I'll leave the rest for the others as I have to rush off and do some stuff xD But good luck on your application, hope to see you around!
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