Level nine gymnast as well as swimmer, coral girl and YouTuber whose vlogs can be seen on her family channel, It's The Donnellys, which has earned over 950,000 subscribers. She is also extremely popular on musical.ly with over 2.4 million fans on her katie8228 account and on Instagram with over 1.1 million followers on her itskatiedonnelly account.
She became a YouTuber with her original Flippin' Katie channel in May of 2015 and accumulated over 100,000 subscribers in just three short months.
In just one month, her "The Great Watermelon Challenge(s)" video accumulated more than 2 million views. By early 2016, the video had over 13.2 million views. She was a level 7 State Champion gymnast in all around, bars, beam and floor in 2016.