Carrie Underwood brought smiles to the faces of Arleigh Williams and Kodi McAlvain. The two share a love for Underwood and their fights against cancer.

9-year-old Williams and 8-year-old McAlvain became friends while both of the girls were beginning their cancer treatments two years ago. Their friendship grew into sisterly relationship for the pair.

According to Oklahoma's Own News On 6, the pair developed such a strong bond that they get mistaken for sisters, McAlvain said "Williams tells people that we are."

The girls even get called twins, Williams said:

McAlvain made sure to show her sisterly love when Williams got sick and had to go to the hospital when the two had tickets to see Underwood perform at the BOK Center. Williams said