- were appointed to the trial court by Governor Brown or Governor Davis (or elected during another administration)
- were elevated to the Court of Appeal by Governor Brown or Governor Davis, and
- are about the same age as other recent high court appointees. Chief Justice Cantil-Sakauye, Justice Corrigan, and the last four U.S. Supreme Court Justices -- Kagan, Sotomayor, Alito, and Roberts -- were all appointed in their 50s.
My research shows 4 or 5 justices who fit the bill. Maybe 6 or 7 others would fit if we expanded the pool to justices in their early 60s. I'll share the results of my research shortly.
(As always, I have zero inside information from people affiliated with the court system. I just checked the judicial bios on the public website. Take a look yourself.)