In a perfect world, the onus would be on Jo Boaler to prove her theories... rather than use our classrooms full of children as lab rats for her experimentation. Unfortunately (and un-scientifically) Jo Boaler does not appear to provide sources for her theories/claims.

Be that as it may, the following barely begins to scratch the surface, but might help a bit?
1) Serving Students with Exceptional Promise
March 9, 2018
STEM Network Working group
Originally Posted by Article on NAGC website
... a video by Jo Boaler has caused some to question the importance of identifying gifted students. This is a response from the NAGC STEM Network Working Group.
2) Research That Supports the Need for and Benefits of Gifted Education
Sally M. Reis
March 2, 2008
12-page PDF file, linked from the aforementioned article on the NAGC website.