The Slow-Paced Opening: The opening scene is trying to tell you the kind of film Roma is going to be. While in the foreground is developing the activity of washing the porch, in the background are the sounds of the city, the sorroundings of that little world (birds, a dog barking, street vendors outside). The sounds of water being agitated, an airplane reflected in the water crossing the frame (which gonna be a motive in the entire film). Cuarón wants you to start to get use to the immersive experience. You start watching the action hovering from above and then, after the opening credits disappear, the camera turns to be parallel to the ground. We, as the camera are, a ghost from the present observing the past. Notes: Those are not "bricks of concrete" but a tile floor. Conclusion: You're parents are not patient viewers or they just love wine more than cinema.
The Unrealistic Household: Well, Cleo and Adela are live-in maids. If you parents noticed they sleep in a room upstairs next to the main house. I'm pretty sure in the opening scene (which your parents missed) Cleo is cleaning up the porch because there was a bunch of those "land mines". The interesting thing is how pointless picking-up dog poop throughout the day really is. 'Cause if they noticed, when Cleo comes to the house after picking-up Pepe from the kindergarden, the dog had already pooped. Maybe they just clean up the porch once a day. Their responsability is to be focused on tending the children and the parents and make sure the interior of the house is impeccable. Notes: "unrealistic dirtiness." I think this term is really vague. Conclusion: This kind of "problems" with the movie, shouldn't exist while criticizing a film. It's a feature within the development of the story but not a flaw for the film.
The Morality of Roma: "my parents took issue with how Cleo - the housekeeping protagonist - ended her narrative character arc with the realization that she “didn’t need a family of her own, because she already had the Sofía household to take care of.” This statement is completely wrong. The development of the movie and the way is filmed is to be distant, Cuarón wants the perspective of the film to remain undjudged. The narrative arc for cleo is to confess that she didn't want her baby to be born, which is something problematic for women in the mexican society back then and right now, to say that they don't want kids for many reasons; for Cleo it was that she's all by herself, not support and no recognizition by the father of the baby, she dedicates all day long to serve other people, when she's gonna have some time for her child? For many women like Cleo in México, they accept the family they serve as a second family because maybe their situation is better that the one they would have back in the town where they grew up with a lot of shortage. So, It's something we don't have to criticize the film for, it's something very common for people like Cleo in México, sometimes is better for them not to have family of their own while there are no chances to offer their children a better living. But that's something that Roma doesn't make a judgement about, but it shows us that these things happens all the time. Conclusion: Your parents have to separate between criticizing the story and criticizing the film. And they need to be open to other life perspectives within different cultures.