I think there is a misconception that Rose was only in Synanon for a few months, but there is somewhere in one of her letters that she says, "it's been almost a year".
Correct I don't have a specific date that info will be in the juvenile record. But the first letter I have was dated Oct 15, 1972. Which places at Syn. She was sent there sometime between 04-29-1972 and Oct 15, 1972.
Opal told me the other day that they were late for Billy's wedding because they have to pick up Rose at Jackson Juvenile facility in MI. She said this was in May but she didn't seem certain of the date.
I found Billy in the Genesse County records, he married his first wife 4-29-1972. This places Rose in Michigan.
Maybe she was sent there in MAY after the semester ended in Emerson.
Based on what we have learned, Rose would not have been allowed to write home for weeks once at Syn.
The letter you are referencing was dated Dec 23, 1972 in red ink pen. With a note in black pen "it's been almost a whole stinking, lousy year. . .Sorry but I just got a stamp! Feb 3, 1973".
Dec 15, 1972 is her Syn split letter. Based on all of this, and the assumption that she was sent there in May, her stay would have been 8 months.