"Machino Machida" is a strangely ordinary name. An unlikely combination that stands out more than the names of the heroines, but with a literally pedestrian meaning.
街田 町乃 /Machi-da Machi-no/
街 street
田 rice field
町 town
乃 of
It doesn't seem to be an obvious pun referencing her role (if it is, it's not as on-the-nose as e.g. Najimi Osana from 'Komi-san'), and it doesn't suggest anything obvious about her personality either. Yeah she is an "ordinary high school student" in contrast with the fantasy heroines, so an "ordinary" name would suit her... But her name is anything but common, it just has a boring meaning. I don't know if this will ever become relevant, but it is pretty odd.
Machino sure seems to have no problem at all just straight up telling her parents and her friend about how a video game character just suddenly appeared in her house.
Machino is not telling her family anything, she's just recapping what happened so far as if she was writing them a letter. Given that she has to do all the household chores (Sofia did some of it in her stead now), she is probably all alone in the family home, with her parents working far away and her sister away at college. Her absent family also explains how she got away with pulling three all-nighters in a row playing the game.