The quote at the beginning, "How does a woman in her 70s end up getting married? It all started when the world shut down.", is Diane narrating, not Carol.
When they are trying on masks, one character says, "It's very Christian Grey." Don Johnson's daughter Dakota Johnson plays Christian Grey's love interest in the Fifty Shades of Grey (2015) trilogy. E.L. James' books are the basis for the plot of the original film.
In the car on the way to Tuscany, Sharon quotes Jack Nicholson's character with the line, "You can't handle the truth!" Nicholson discovered Mary Steenburgen in the reception room of Paramount's NY office and cast her as his leading lady in Goin' South (1978).
Sharon [Candice Bergen] looks at Vivian's hand as she shows off her engagement ring and incredulously says, "You're engaged?!" She also said this in Sweet Home Alabama (2002) as Mayor Kate Hennings to her son Andrew, played by Patrick Dempsey.