Lori Alan (born July 18, 1966) is an American actress, comedian, and voice actress. She has played a long-running role as Pearl Krabs on the animated television series SpongeBob SquarePants. She also voiced Diane Simmons on Family Guy, the Invisible Woman on The Fantastic Four, and The Boss in the Metal Gear video game series. Alan is active with animal rescue and politics, and she currently lives in Los Angeles.

Answer this question based on the passage: who does the voice of diane on family guy? Let's have some stream of consciousness first.
To answer the above question, the relevant sentence is: She also voiced Diane Simmons on Family Guy, the Invisible Woman on The Fantastic Four, and The Boss in the Metal Gear video game series. So, the answer is Lori Alan.