RORY (looking at photo of Sherrie): Nice looking lady.
LORELAI: Mm hmm. Like a young Tammy Faye Bakker.
RORY: But prettier than that.
Tammy Faye Bakker, born Tamara LaValley (1942-2007) was the ex-wife of television evangelist Jim Bakker (born 1940). She and her husband ran a televangelist program called the PTL Club, founded in 1974; it was dissolved in 1989 when Jim Bakker was convicted and imprisoned on indicted on numerous counts of fraud and conspiracy. Tammy Faye divorced Jim in 1992, and married Roe Messner, a church building contractor (so by this stage she was actually Tammy Faye Messner).
Tammy Faye was known for her eccentric and glamorous image, and her views which often diverged from mainstream evangelical Christianity. For example, she supported the LGBT community, and reached out to HIV positive patients at the height of the AIDS epidemic. She was diagnosed with colon cancer in 1996, so was already terminally ill when this episode aired.