According to known scooper Daniel Richtman (aka @DanielRPK), Krysten Ritter's Jessica Jones is rumoured to appear in the series. Despite the news being just a rumour at this time, Richtman has had a good track record with his scoops in the past.
Ritter starred as Jessica Jones across three seasons of her own series on Netflix, and a crossover series with fellow Netflix superheroes titled The Defenders. However, while the characters were vaguely considered part of the Marvel Cinematic Universe, Netflix contractual agreements would not allow the characters to appear in Marvel Studios properties until two years after the Netflix series had been cancelled.
While two years have passed and Marvel Studios can now use the Defenders characters in their films and Disney+ streaming series, the time has only just expired. However, She-Hulk is not due to release until at least 2022, giving the writers and Marvel plenty of time to include Jessica Jones into the script.
The time frame also would not be an issue, due to reports stating that Charlie Cox's portrayal of Daredevil is also reportedly going to feature in Jon Watts' third Spider-Man film alongside Tom Holland. Considering Watts' Spider-Man 3 is due for release at the end of the year, it stands to reason that the creators of She-Hulk will have more than enough time to include Jessica Jones into their plans.