Janel Moloney (right), courtesy Decumanus, via Wikipedia
Janel Moloney is an American actress, best known for her role as Donna Moss on The West Wing. On House, M.D., she portrayed Maggie, the dying mother in the Season 4 Christmas episode It's a Wonderful Lie.
Moloney's early work was largely in TV movies. However, she hit the big time on The West Wing in 1999 and since has had featured roles in Amber Frey:Witness for the Prosecution and Brotherhood.