Betty DiMello is the receptionist at the Reproductive Biology Research Foundation. She is portrayed by Annaleigh Ashford.
In the first season, Betty is a prostitute working at a brothel. She allows Bill to examine her having sex with people. When Bill moves the study to the brothel, Betty asks Bill to help her get her tubes untied. The procedure is unsuccessful.
Betty is now married to Gene Moretti, a rich man who produces pretzels. What Gene doesn't know is that Betty can't have children because she hasn't told him. Gene is dissapointed with the news when Bill tells him that Betty is infertile.
Meanwhile, Helen, Betty's ex-girlfriend, returns and tries to wedge herself between Betty and Gene. Helen and Betty have sex and are caught kissing by Helen's "fiancée", who tells Gene. Gene and Betty break up and she gets together with Helen.
When Bill starts his own clinic, Betty joins as a receptionist.
In the third season, Helen wants children, so Betty enlists Austin to pretend to be Helen's husband so Helen can be impregnated. Helen then becomes pregnant.
Helen gives birth, but dies after the child is born. Betty is even more horrified to discover that Helen's disapproving parents will keep custody of the baby because she and Helen were never married, and therefore not family. Betty wants her and Austin to get married and, since it was his sperm that the baby was born from, the two will fight for custody and get a divorce once the baby is theirs.