Grace Livingston Hill 
Crimson Roses 

Alone in the city, Marion struggles to survive. Desperate to find a small bit of happiness, she impulsively spends some of her hard earned and terribly meager money on a season ticket to the symphony.
On the night of the second concert, something wonderful happens. There, on Marion’s seat in the concert hall, lies a beautiful, dark crimson rose! And every week after that, she finds yet another beautiful, fresh rose waiting for her at the concert hall! Marion is torn between joy at receiving the beautiful flowers and worry at not knowing who could be sending them.
Then, suddenly, Marion’s mystery flowers lead her into the confusing world of a wealthy man—and make her the target of a society beauty’s dangerous envy…