tattlesome

From tattle +‎ -some.

tattlesome (comparative more tattlesome, superlative most tattlesome)

1. Characterised or marked by tattling
   • 1989, Gordon Parks, The Learning Tree:

     The apparition frightened her, and she had dropped the plate. Newt thought of Priscilla as most boys his age thought of older sisters—meddlesome, tattlesome, scary, curious and unsociable.

   • 2004, Tenn' Enomentielva: A tale of many partings - Chapter One - Beginnings of Silver:

     Now, before my reader believes that Arwen was being tattlesome, you must understand that very often things - most times bones - were broken when the twins fought, and Arwen was under strict orders to report any such offenses while they were still young.