Its got to be an actrsss whose well known for certain well loved characters, but not busy she's expensive.
What about Tia Carrea? Jeri Ryan? Terry Farrel? Nina Visitor? Alexandra Daddario (top choice), Trish Helfier?
Aimee Garcia played Ella on Lucifer, but she's a HUGE D&D nerd, like she help do a D&D comic book. Famous and well likely, but not insanely expensive, already a major part of the D&D Sphere.
Alternately, could be a female member of critical role. They aee well qualified.