I don't think we've seen a recent body shot of Lia actually and her meds do effect her weight, but it was speculated she was cosplaying from recent tweets. Did Airi, Lia or Shiina say at all that all of them cosplayed? What I picked up is that Lia and Airi cosplayed at least 1 day, not sure if all of them did or if they did it more then once, or if they actually shopped together. I didn't listen to all of the streams though, but it did sound like Shiina at least brok eoff alone for some things. For Airi I'd look out for medium bust or bigger Asian woman likely with a zipper in the front, but possibly the zipper could be under another layer. She is probably like 5'5 as I have not heard her described as tall or short.
https://arknights.fandom.com/wiki/Mizuki E What Lia might have cosplayed
I'm happy for Airi moving on from the black company soon