Question: Finding Dory features the voice of an actress from "It's Always Sunny in Philadelphia" who plays what character on that show?

Context paragraphs:
StormRider: StormRider was a simulator ride at Tokyo DisneySea.  It simulated going into a weather storm in a futuristic airplane (a "StormRider") to dissipate the storm.  The attraction opened on September 4, 2001, in the Port Discovery land of Tokyo DisneySea.  The attraction closed on May 17, 2016 and replaced by a new Finding Nemo/Finding Dory simulator ride called Nemo & Friends SeaRider.

The Waitress (It's Always Sunny in Philadelphia): The Waitress is a fictional character on the FX, now FXX series, "It's Always Sunny in Philadelphia", and is portrayed by Mary Elizabeth Ellis.  The Waitress is a waitress at a Philadelphia coffee shop who is frequently stalked by an enamored Charlie Kelly.  The Waitress's real name is never revealed and no one in the gang can remember it despite knowing her for several years.

Finding Dory: Finding Dory is a 2016 American 3D computer-animated comedy adventure film produced by Pixar Animation Studios and released by Walt Disney Pictures.  Directed by Andrew Stanton with co-direction by Angus MacLane, the screenplay was written by Stanton and Victoria Strouse.  The film is a sequel/spinoff to 2003's "Finding Nemo" and features the returning voices of Ellen DeGeneres and Albert Brooks, with Hayden Rolence (replacing Alexander Gould), Ed O'Neill, Kaitlin Olson, Ty Burrell, Diane Keaton and Eugene Levy joining the cast.  The film focuses on the amnesiac fish Dory, who journeys to be reunited with her parents.

Boldly Going Nowhere: Boldly Going Nowhere was a proposed American television show for Fox.  Rob McElhenney, Glenn Howerton, and Charlie Day, the producers and stars of "It's Always Sunny in Philadelphia", created the show along with their "Always Sunny" writers' assistant Adam Stein.  While they did not plan to star in the show, they were the executive producers.

Finding Nemo (franchise): Finding Nemo is a CGI animated film series and Disney media franchise that began with the 2003 film, "Finding Nemo", produced by Pixar and released by Walt Disney Pictures.  The original film was followed by a sequel, "Finding Dory", released in 2016.  Both films are directed by Andrew Stanton.

Nemo &amp; Friends SeaRider: Nemo & Friends SeaRider is a simulator ride at Tokyo DisneySea at Tokyo Disney Resort.  It based on Disney/Pixar film Finding Nemo and Finding Dory.  Nemo & Friends SeaRider utilizes the same ride system as its predecessor, StormRider.

Gregory Grene: Gregory Grene is an American musician based in New York City, who grew up in Chicago and County Cavan, Ireland.  He is the son of the classicist David Grene.  With his band The Prodigals, he writes and plays a style of music that melds Irish traditional and rock influences, and he has also recorded a solo album, FlipSides (2008), with musicians ranging from John Doyle, former guitarist with Solas, to Tony Cedras, a multi-instrumentalist who has played in Paul Simon's band since the Graceland tour.  Grene's music has received critical acclaim over the years, was included in the Rough Guide to Irish Music compilation, and was featured in the soundtrack for "Pride and Glory", a movie starring Ed Norton, Colin Farrell, Jon Voight and Noah Emmerich, as well as on television in the ABC show "Mercy" and the FX series "It's Always Sunny in Philadelphia.

Albert Brooks: Albert Lawrence Brooks (born Albert Lawrence Einstein; July 22, 1947) is an American actor, filmmaker, author, and comedian.  He received an Academy Award nomination for Best Supporting Actor for 1987's "Broadcast News" and was widely praised for his performance in the 2011 film "Drive".  His voice acting credits include Marlin in "Finding Nemo" (2003) and "Finding Dory" (2016), and recurring guest voices for "The Simpsons", including Russ Cargill in "The Simpsons Movie" (2007).  He has directed, written, and starred in several comedy films, such as "Modern Romance" (1981), "Lost in America" (1985), and "Defending Your Life" (1991).  He is also the author of "2030: The Real Story of What Happens to America" (2011).

Willem Dafoe: William J. "Willem" Dafoe (born July 22, 1955) is an American actor.  A member of the experimental theatre company the Wooster Group, he was nominated for the Academy Award for Best Supporting Actor for his roles as Elias in Oliver Stone's "Platoon" (1986) and Max Schreck in the comedy-horror film "Shadow of the Vampire" (2000).  His other film appearances include "The Last Temptation of Christ" (1988), "Mississippi Burning" (1988),"The English Patient" (1996), "American Psycho" (2000), the "Spider-Man" trilogy (2002–2007), "John Wick" (2014), "The Grand Budapest Hotel" (2014), and "Justice League" (2017).  He has also had voice roles in "Finding Nemo" (2003) and its sequel "Finding Dory" (2016), "Fantastic Mr. Fox" (2009), "John Carter" (2012) and the recent adaptation of "Death Note" (2017).

Kaitlin Olson: Kaitlin Willow Olson (born August 18, 1975) is an American actress and comedian.  She began her career in the Groundlings, an improvisational group in Los Angeles, California, and had minor roles in several television series before being cast as Deandra "Sweet Dee" Reynolds on the FX black comedy series "It's Always Sunny in Philadelphia" in 2005.

Supporting paragraphs: Finding Dory Kaitlin Olson
Answer: Deandra "Sweet Dee" Reynolds