Answer:
They were Mr. Peale and Nathaniel Benson.
Nathaniel Benson was sending her "flowers".
Step-by-step explanation:
The novel "Fever 1793" by Laurie Halse Anderson tells the story of Mattie Cook amidst the spread of yellow fever. The story follows Mattie through the hardships of running away from home, the death of her grandfather, yellow fever, and helping others.
While walking back from the orphan home with Eliza and Nell, Mattie remembers Mr. Peale, "the one who gave all those strange names to his poor children" and "Nathaniel Benson".
Nathaniel Benson was sending her "flowers" through the shutters, and had previously sent "a painting, a vase full of delicate flowers, bright blue, lavender, and red carefully painted on a scrap of wood."