Equestrian shirts such as this one https://www.amazon.com/dp/B008YJL2H4/?coliid=IWOPOXHN8BG6P&colid=2Q44RSRQ43W52&psc=0&ref_=lv_ov_lig_dp_it may fit your needs. I'm not sure about shipping to Europe though
If anyone’s into Polo Bears I found these cute $10 socks on Amazon (not prime) with a nice variety of bears, including hot cocoa tuxedo bear which is a great holiday sock. I’ve had a hard time finding any Polo Bears on DHG or AE (TB is still beyond my capabilities) so I might pick a few of these up.
Do you know about what size she is? Im autistic so I have a lot of sensory issues related to clothes. My favorite leggings are vera wang from kohls (a lot of my clothes are from Kohls, they tend to have comfy stuff at reasonable prices) I like to wear them with a tunic top like this: amazon tunic, or a flowy shirt from torrid's super soft line. Depending on her style hot topic has a lot of cute tops, I typically get at least an XL (and I'm a size 14) but they do have plus sizes online. Also, target's graphic tees are super cute, and come in a wide variety of sizes.
Joe's on Amazon is nice breathable and cheap. I can't wear a normal polo to save my life- I hate them.
What an awesome contest! Hm.. I'm starting work again very soon and could use a work shirt since I don't currently have any that fit or aren't full of holes.