Thank you!!
So some of the things are unavailable, but it'll hopefully at least give you an idea of what to search for! Here's how to costume turned out: https://www.reddit.com/r/heathersmusical/comments/dpz048/happy_halloween/ I crocheted the scrunchie myself. I bought chains from Joanns for the jacket but got too lazy to do it. I still think it looks fine without it. I couldn't find her neckpiece for the life of me, so I said heck it.
Shirt: https://www.amazon.com/gp/product/B07NM3MQHW/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1
Jacket:
https://www.amazon.com/gp/product/B01MAUKC6W/ref=ppx_yo_dt_b_asin_title_o08_s02?ie=UTF8&psc=1
Skirt:
https://www.etsy.com/listing/493145577/pleated-plaid-long-skirt-17-18-henley?ref=yr_purchases
Socks:
https://www.amazon.com/gp/product/B075DG58LZ/ref=ppx_yo_dt_b_asin_title_o08_s03?ie=UTF8&psc=1
Shoes:
https://www.amazon.com/gp/product/B076DLNR8X/ref=ppx_yo_dt_b_asin_title_o08_s03?ie=UTF8&psc=1
Croquet set:
https://www.amazon.com/gp/product/B07P1RPHL4/ref=ppx_yo_dt_b_asin_title_o08_s05?ie=UTF8&psc=1
Football Jacket: https://www.amazon.com/gp/product/B01NCAV59L/ref=ppx_yo_dt_b_asin_title_o08_s03?ie=UTF8&psc=1
Jacket Patch:
https://www.amazon.com/gp/product/B07FKLZ5F1/ref=ppx_yo_dt_b_asin_title_o08_s04?ie=UTF8&psc=1
If you need anything else let me know!