The U.S Postal Service Website states that if First Class Packages are shipped on or before December 18th they will arrive by Christmas Day.
Due to the current state of the U.S. Postal Service, we (A Treasured Home) unfortunately cannot guarantee arrival before Christmas day. We generally need 3-4 weeks to ship orders with any 3D printed merchandise and 1-2 weeks for everything else. If you have any additional questions about shipping please email us at email@example.com. We are currently working overtime to get all packages out as quickly as possible. We want you to have your items before the holidays too.