paola, I'm checking the dates for each nomination and it seems most sites that I find except for Goodreads list The Mother as first published in 1920, such as
this Google search. I've used 1920 as its date for the nomination list, but I will trust you and change it back to 1919 if you are confident of it. It doesn't matter much really since both dates are eligible but I wanted to make clear why the date in the list was different from your post.