You have a Maid that lives with you, a Tutor that lives with you, and a Neighbor that is also your Maid's sister and apparently lives with you. Except... there's something wonky about all those people living in the same house. Shouldn't "Neighbor" Julie at least live next door?
Here's what you do:
Start a New Game, ignore the input prompts and leave the default information for the MC and Linda being the "Maid" and you're her "Client." Once you clean up your laundry and get out into the hallway, click on Emily's door and it tells you "That's Sis' room" before you even meet the character and are given the chance to identify her as a Tutor. That should be a clue right there. Zip through the next few scenes until Emily and Julie arrive. Keep their default info, and notice how the game needs you to specify their relations with "you call them X, they call you Y" prompts. Got all that? Okay. Good. Now go back to the title and start over. Get to Linda's introduction and change her name to Mom. It completely skips the Maid/Client questions because it somehow knows the MC is her Son. Get to Emily and Linda, keep their default names and set relationships to Sister and Aunt respectively and it won't even question what the characters should call you in return. It's almost like the game was meant to use those instead of what it tells you to enter. Weird, eh?