At the end, all three siblings go off to college: at the same time. How could all three be the same age, unless they were twins, adopted or a combination of something else? No mention of this quandary is explained in the story. However, it is more likely that two children were already in college when the third one was entering college.
The children ordered the "Grandma" with long hair, but she wore her hair short and up instead of down. However, they did not specify that she should wear her hair down. Perhaps the children like the look of long hair worn up.
At the beginning of the episode when George Rogers is talking to Aunt Nedra in the living room, the boom mic is visible in the far left-hand corner.