I have the book, “Documents on Fatima and the Memoirs of Sister Lucia,” by Father Robert J. Fox.
The book contains the first documents on the apparitions.
The OP quote is from this, but slightly different in words.
At the Apparition on September 17, 1917
After Lucia asked the Blessed Mother to perform a miracle, the children were given this answer,
“On the last month[October], I will perform a sign in the sun, so that that may believe.
And St Joseph will come with the Child Jesus to give a blessing to the world, and
Our Lady of the Rosary. Afterwards, Our Lady of Sorrows and Our Lord.”
Lucia states that during the last apparition she did not see the miracle of the sun, but instead saw what the Blessed Mother had told her as above.