In the two photos posted by Rain, the sisters are shown posing in front of a large light-up Christmas decoration.
"Eating cheesecake, passing out on ride and waiting 30 minutes to get a picture in a Christmas bulb!" Rain captioned the photos. "I wouldn't want to spend our birthday week any other way."
While Rain regularly updates fans on what she's up to, this is the first time Birdy has been seen in quite some time.
See the pictures below.