Her legal contributions to Team Flash more or less came to an end after Barry was exonerated with a little help from Ralph Dibny, but she was still a big part of the plot once she began developing pregnancy-related superpowers.
All things considered, Danielle Nicolet’s promotion (as reported by Deadline) to regular status isn’t all that shocking.
Cecile was a major character in the fourth season, especially the latter half as Team Flash had to deal with Barry’s incarceration and Cecile’s pregnancy took some unexpected twists and turns.
As if she didn’t already have enough to worry about!