7 LITTLE Johnstons' star Anna has skipped out on her family's vacation to Puerto Rico despite being invited, The U.S. Sun can exclusively reveal.

Fan-favorite Anna, 24, was notably missing from cheery family photos from the trip posted to the Johnston's official Instagram page last month, leaving followers curious about her whereabouts. The U.S.

Sun exclusively obtained a direct message exchange between a fan and the account, claiming that Anna was expected on the getaway but opted not to go. On a post featuring her sister, Emma Johnston, 19, the fan asked, "No Anna?" The blue-checked account quickly responded: "She chose not to go. Plane ticket was purchased for her, and plans were made for her to attend with the family.

" Anna appeared to be the only family member not on the getaway, which also included Liz Johnston's baby daddy, Brice Bolden, 25, 24-year-old Jonah Johnston girlfriend Ashley Saltz, and 18-year-old Alex Johnston's girlfriend Allie Smith. The TLC star previously led fans to believe she wasn't asked to join the group after a fan questioned the Russian-born adopted daughter of Trent, 48, and Amber, 45, why she was not on the filmed vacay with the rest of the Johnstons. She shrugged it off, saying she was "not invited.

" This news didn't surprise fans, as Anna is known for being the family's proverbial "black sheep" due to her constant clashes with her mom, Amber. Online threads exploded with comments like, "Lord that family is horrible to Anna. Amber and [her sis.