Continuity mistake: In the bar scenes, the Dos Equis beer bottles change position pretty much after every shot. Sometimes there are three bottles in a row, then two, then three again. And when the bottle of nearly full beer gets tipped over, not only is there no spill, but no foam generated from the bottle being shaken the way it was.
Continuity mistake: Everett's car is not one but at least three cars. The first time we see it, there are no stickers on Mer's side, but there are some on Everett's side. Later, there are stickers on Meredith's side only and later still stickers are on her side but have changed.
Continuity mistake: When the family are looking at the wedding ring that has been put on Julie's hand, the father's glasses change from being on top of his head to on his face and then back again depending on the shot used.
Continuity mistake: For the first few minutes of the film (as all the children are arriving and getting situated) Diane Keaton's sweater that's tied around her shoulders disappears and reappears at least twice. It's a contiguous scene with different shots so there would be no reason or time for her to remove it and replace it.
Continuity mistake: During the dinner, when the whole family is sitting down together, the candles on the table change height. They go back and forth from tall to short throughout the whole sequence.
Continuity mistake: At the beginning when Everett and Meredith are shopping, just as Everett has finished buying a gift, there is an old man with a hat and a grey beard and an old woman with grey hair next to him. The shot cuts to the cashier. Then in the next shot of Everett, those two people aren't there anymore.
Continuity mistake: When Kelly is telling everyone to welcome back Meredith as a family, Ben is wearing a watch. When he says, "I'm ashamed of all of you" the time on his watch reads 11:45. But when he says, "You can't marry her", the time on his watch now reads 12:00 despite only a few moments passing.
Continuity mistake: The picture frames that are gifted by Mer to the family are different from the picture hanging on the wall in the final scene hanging on the wall. (01:19:10 - 01:39:15)
Answer: It is probably the lady's husband who was pregnant the entire time...right?