*Mildred Fry (December 6, 1922 - February 13, 2000) was the beautiful and curvaceous fiancée to Enos Fry, and the mother of Yancy Fry, Sr.
Since she was never married to either Enos, Philip, or (as far as we know) any other member of the Fry family, and her maiden name is not mentioned, it's only for nomenclature purposes that she is called "Mildred Fry" in the wiki.
She was the mother-in-law of Mrs. Fry, and the paternal grandmother of Yancy Fry, Jr. and Philip J. Fry.
She was the paternal grandmother-in-law of Yancy Jr.'s wife, Leela and Jrrr.
She is the paternal great-grandmother to Philip J. Fry II.
She is also the step-great-grandmother of Kif Kroker's Offspring (Amy's adoptive children).
After her grandson traveled into the past, a series of events transpired, ultimately leading to Mildred having an affair with her grandson and conceiving her son Yancy.
In 1947, Philip I encountered her as waitress in a diner at an army base in Roswell, New Mexico when he, Leela, Bender, Dr. Zoidberg, and Professor Farnsworth traveled back in time. While with Enos, Philip was struck by her beauty until he learned who she was and changed his perspective.
Afterwards, she tended to Leela and Farnsworth (unaware that he was one of her descendants) while confused by their orders and serves them chili dogs. Soon she receives word Enos was killed in a house that turned out to be a test site for an atomic bomb, she was consoled by her grandson who Mildred felt reminded her deeply of Enos (unaware that Philip I was her own grandson) and asked if he would walk her home.
Once there, she grieved over her fiancée but immediately began flirting with Philip I, making him uncomfortable. In an effort to distract Mildred, Philip I asks her to make him sugar cookies to cheer her up, but Mildred, refusing to be deterred, rips open the top of her dress and thrust her bra covered breasts at him after seductively asking "How about these cookies, sugar?". Philip I was hesitant about having sex with Mildred, but got over it, incorrectly reasoning that since he still existed and Enos was dead, Mildred wasn't actually his grandmother. Before he could finish his sentence, Mildred quickly kissed him and the two had unprotected sex on the couch which soon moved to the bedroom. As a result of sleeping with Mildred, Philip I conceived his father and became his own grandfather. This act also made his father inbred since his parents were direct relatives.
The next morning, Philip I learned from Professor Farnsworth that Mildred was really his grandmother and pointed out as Fry saw that Mildred was acting like his grandmother in his own time. She suddenly wore reading glasses and was hard of hearing. Horrified, Philip I asked if Mildred was in fact his grandmother who his grandfather was before Hubert told him that in sleeping with her it made him his own grandfather. This disgusting act freaked him out and he went about screaming and running around uncontrollably.
Nibbler was aware of what Philip I did to Mildred and commented in "The Why Of Fry" that "the nasty from the past-y" cost him the delta brain wave and thus, his born immunity to the Brainspawn.*