A quick Westlaw SCT-BRIEF search found only 7 briefs titled briefs of amica curiae, the feminine version of amicus curiae (though I suspect that older briefs are underrepresented in that database). But it turns out that two of those were signed by professors at George Mason (a school with which I have very amicable relations) — a brief co-signed by Ilya Somin on behalf of Prof. Jane Jacobs in Kelo v. City of New London, and Prof. Leandra Lederman’s brief on behalf of herself in Ballard v. Commissioner.
On a non-Virginia note, I also noticed that a 1936 brief in R.C. Tway Coal Co. v. Glenn was filed on behalf of the State of Washington as Amica Curiae (or at least so the Westlaw version reports). That might be a reflection — albeit an uncommon one — of the tradition of referring to states as “she,” though I can’t be sure.