Casas' Wikipedia entry mentions that he came from a wealthy family. But she did not, and his family did not approve of him marrying her, which he did not do until 1922. Their relationship began in 1906 when he saw her selling flowers and lottery tickets outside a Plaça de Catalunya cafe.
She served as model for a number of advertising images, many drawings, and paintings. Examples are presented below.
As mentioned, she had been a flower seller.
For some reason, this is said to be Casas' best-known painting of her.
An example of her in Casas' commercial work.
Undated, but probably painted about the same time as the previous painting.
She was born in Barcelona, but here Casas depicts her in Cordova costume.
She was about 37 years old when this was painted: still an attractive woman.