Doreen Knitting Pattern Books by Nell Armstrong

On the back cover of Doreen Curtain Pulls, Volume 98, is this small advertisement referencing 5 of her previous books.

 I have four different books so far and each one are under the Doreen name with, by Nell Armstrong, always referenced, along with the volume number for the specific book.   Below this advertisement was a notation that if your local dealer (remember this was 1949), does not have the books, to write directly to the company - Doreen Knitting Books, Lowell, MA.

So, who was Nell Armstrong of Doreen Knitting Books?     I spent a good hour searching Google, and all I came up with was she copyrighted several books between 1947 and 1952.   The books were copyrighted under her name, Nell Armstrong, not a company name with Doreen being part of the book title.    Searches for the company name itself netted nothing.    I have book 105, and these are in the 90's.    This number series would imply that it started at Number 1, however, I could find no reference in Google to any books before earlier than the 90 series shown above. 

So, who was Nell Armstrong of Doreen Pattern Books?    And how many pattern books did she issue?    I don't know.    Do you know anything about her or her company?  

Thanks for dropping by,
Lorrie