Yesterday, Father Evaristus said that chastity inside and outside marriage is most certainly what preserved the bodies of the incorrupt saints.
The parents of Rita (1381-1457) arranged a marriage despite her repeated requests to be allowed to enter the convent. Her husband, Paolo Mancini, was a rich, quick-tempered, immoral man with many enemies. She endured insults, physical abuse, and infidelities. Bad guys killed him in the eighteenth year of their marriage. It was at that point that she entered the convent. She is an incorrupt.
Then there is Bernadette (1844-1879), whose body the nuns washed during one of the exhumations, which caused black spots to appear on her face. A thin layer of wax was applied to her face to cover up the spots. As you can see from the close-up, all the facial features, bones, and eyelids remained intact. She is an incorrupt.
What we see of Cecilia (early 200's), a married woman, is a marble sculpture, not her body. I looked her up on Wikipedia, which states that in 1599 Cardinal Sfondrati saw the remains and reported her incorrupt.
Father Evaristus said we are expected to return our own bodies to God Almighty on His schedule!