This meal would be in her duodenum in either situation.
The small intestine is the longest part of the process in pushing her meal through, specifically the duodenum is the first stage of this and moves the food along in a process that takes several hours to exit into the next point.
How does she eat at 6, then again at 7:30 and this meal has completely emptied from her stomach, and passed through her duodenum in 3-4 hours? its highly improbable if not impossible that her duodenum would be completely empty
u are also trying to minimize the meal amount and the type. I am not sure what the pizza had on it, but it certainly had cheese which is something that takes possibly the longest to digest. i would assume 2-3 slices of pizza and some apple crumb whatever is a moderate meal for a girl of merediths size....its not huge, its not insignificant, lets just run with "normal".
I am not privy to the science of it but obviously certain foods take longer to start processing out of the stomach with meat and cheese being very high on the list of things, and liquids and fruits etc being low. it seems fat content among other things play a large role in time of this, which makes for a very slow process. again i dont know enough but knowing what she ate someone who is educated might be able to discuss what al this meeans
The chart you showed provide a rate to where the meal is being emptied from the stomach, and into the duodenum and it says there is typically a lag time of 30 minutes before this starts happening.
So how long from there does the meal stay in her duodenum?
Again, to be clear this meal would need to completely pass through her stomach and duodenum entirely, not sure about the entire small intestine