16-year-old Helena Muffly wrote exactly 100 years ago today:
Thursday, November 30, 1911: Today is Thanksgiving. We didn’t have such a terrible sumptuous repast either. I would have liked to have had a piece of a turkey gobbler and a dish of ice cream, but we were far from that. I sat at home all day doing miscellaneous jobs which I didn’t relish any too well. Rufus went up to McEwensville this afternoon, to get some of her ever-increasing finery made which she is going to glow in at the institute. One is a piece of embroidery which I presented to her last Christmas but as she at that time was too poor to buy the material to finish it and most too indolent to make it even if she had it. It has lain unmolested till today. There! I’ve filled up the remainder of this page.
Her middle-aged granddaughter’s comments 100 years later:
In this entry Grandma refers to her sister Ruth as Rufus. Ruth was a teacher at a nearby one-room school house and was probably preparing to attend a teachers’ institute (professional development meeting) in a nearby town.
Grandma may have given Ruth an embroidered collar and jabot.
Thanksgiving in 1911
Today Thanksgiving is never this late in November. A hundred years ago it was held on the last Thursday in the month. And, in 1911, the very last day of the month was a Thursday.
In 1939 President Franklin Roosevelt made Thanksgiving the fourth Thursday in the month by proclamation. Federal regulations enacted in 1941 made the change permanent. A very late Thanksgiving shortened the Christmas shopping season—and the change to the fourth Thursday was seen as a way to provide an economic boost to the economy.
Repast
Grandma used the term repast in her diary entry. It is an archaic word for a feast.
A Hundred Years Ago 
It sounds like your grandmother’s family didn’t do much visiting or celebrating on Thanksgiving! I was wondering why the date seemed so late in the month. My dad was about 17 when the change was made – I’ll have to ask him if he remembers anything about it. I’m looking forward to reading what your grandmother recorded about Christmas!
I’ve also wondered why the family didn’t really seem to celebrate Thanksgiving. It will be interesting to hear what your father says.