Can't be. She has black hair. Trisha has brown hair.
Actually, what jjj14 wrote is true, Sloth also has the ability to shape-shift, although to a lesser extent than Envy. Specifically, when she poses as Bradley's secretary, she has Trisha's brown hair and normal looking green-ish eyes. When she reveals her true nature she shifts to black hair and the slitted purple eyes typical of a Homunculus. I am inclined to believe this is probably her in the image. Amusingly, the only three possible explanations for this situation are all incestuous. This is either Trisha, Sloth, or Envy. Trisha is Ed's mom, Sloth is Ed's resurrected mom that came back slightly wrong, and Envy is his 4 centuries older resurrected half-brother that came back *very* wrong, if we go by the 2003 anime canon.