Bill and Margaret are hinted to be the original owners of the house. The developers left the players clues about them by creating house events about notes. They owned the house long before the player's Virtual Family moved in, most likely dying before your character moves into the house.
The Sad Note
A scrap of paper, neatly and perfectly folded and placed deliberately in a crack, reads:
My Dearest Margaret,
Of course you are right, I see it now. We will have so many children. We will, of course, continue construction of the house with all haste. I am sorry I ever doubted you.
Yours in life and beyond,
The Funeral Book
A book, found among some dusty volumes on the old bookshelf, contains the names of people attending a funeral and wake that was apparently at this house many years ago. Condolences are scribbled from a number of people, apparently to a widow named Margaret.
Deed of Purchase: Empty Land at 100 Virtual Lane
Name of Purchaser: Bill
Marriage Status: Single
The Angry Note:
This house is already too big for the two of us. I don't understand why you rehired the workers. I will return a week from Wednesday, and we will discuss.
The angry note was found in a dusty space behind a bookshelf.
The Room Specification:
A scrap of paper was found between the floorboards, with construction specifications on it, and this note:
The 3rd room is to be built adjacent to the eastern wing, and should have room for 3 little boys and girls and their beds and effects. It should be the same dimensions, approximately, as the girl's room. Please advise on time and cost measures.
The Adoption Response
We are sorry for any offense that you inferred from our response to your husband Bill's inquiry regarding services at our agency. We will not contact you again.
Bill, I would be very pleased to attend your house warming. I should be delighted to also bring my sister, Margaret, and my cousin Lilian, if it would not be any imposition.
The Couple's Story
A long time ago, a young man named Bill purchased land, starting with the deed. He was rich and so he started building a house, and had a party, hence the RSVP. His soon to be brother in law, Mason had a sister named Margaret, who attended the party. Bill and Margaret then fell in love and began dating.
They get married and continue with the house. Soon they run out of money... and Bill goes on a business trip hence the fact that one of his letters states that he will return a week from Wednesday. Margaret wants to have the house built the way she wants it and so she writes the room specifications. Bill knows this and sends her the angry note stating his opinion that she shouldn't rehire the workers because the house is too big. Bill wants to have children and sends the virtual Adoption letter. Margaret turns down, hence the adoption response. Bill sends her the sad note, realizing something.
Bill dies in an accident on the way home, and his funeral was in the blue room next to the 2nd restroom. That is why your friends keep smelling that room. It also explains the funeral book event. Margaret dies in the same room, which is soon destroyed. The vandalism in the central room and the trash are caused by squatters, who had been able to get in via the unfinished parts of the house. The rest of the damage was caused by weather and age.