Female researcher

The female researcher is an unnamed female medical researcher.

History
She was on the team that created the drug Focusyn, which was given to Bart causing him to rampage in a tank.

She is later seen at the Mayo Clinic performing tests on Mr. Burns.

She later works at the Screaming Monkey Medical Research Center and discovers that Homer had a crayon lodged in his brain.

The female researcher and her male counterpart are both seen before and during the events of Trappuccino.

She is also seen outside church having seen Marge's calender.

She is seen wearing a blue hat during Easter celebrations, she is seen talking to Mayor Quimby.

Behind the Laughter
Most of the times she appears her look is slightly different, in Season 11 she has red hair, in "HOMЯ" she has blond hair and no glasses, in The Simpsons Movie she once again has red hair, in "The Devil Wears Nada" she has brown hair and in her most recent appearance in "Dark Knight Court" her hair is black.