Your buyer is being unreasonable
USPS won't consider it missing before thirty days. You can call consumer affairs but they won't be able to do anything with it being this early. I had a package shipped in early Nov that got here in mid January. They do show up eventually. You should contact PP and let them know you shipped and its only been a few days but you are worried bc she is being so unreasonable.
Mama to B and E, Wife to E
Parenting with Hugs and Terror since 2011