This personal piece gives us information on the relationship between Berthe and her sister, Edma. The sibling is dressed in a dark long outfit, whilst holding a white umbrella by her side. She also has a matching black hat perched atop her head. She is sat on a stone bench which stretches off the canvas, and some flowers can be found to her right hand side. She stares off to our left hand side, with strong facial features which signify an attractive, young woman of a relatively privileged background. Behind her are very loose details pertaining to elements of the park, with a thick mass of green tones as well as the odd thin brown line running vertically to signify trunks. She produced this using watercolours and worked within this medium in a consistent manner within one particular part of her career.

See also The Artist's Sister at a Window, with Morisot featuring her family and friends many times within her portrait paintings. Additionally, there would be study sketches for some of these artworks, most commonly when working indoors where more time was available. She found those close to her more accessible for her work and she would not have to pay to hire professional models which could prove expensive at that time for someone who essentially specialised in this particular genre. There was also the advantage of knowing these people intimately, and so their characters could be incorporated into the work, where as with models the artist would have to impose their own ideas over the image, which may not have been accurate to the particular individual. Morisot also worked with emotion, hence the long and free brushstrokes, and so it made sense to include people that meant something to her within some of these works.

Additionally, it must be remembered that other Impressionists would also feature those close to them within their work, with Monet, for example, including his wife Camille many times. Some of her depictions actually rank amongst his most famous paintings of all. Morisot, by contrast, would feature siblings, children and friends fairly commonly and liked to vary the ages of her subjects in order to make her oeuvre as interesting and varied within that genre as was possible. Women and girls, of course, were a more common choice for her and so it was inevitable that Berthe's sister can be found several times in paintings and drawings. In the example of The Artist's Sister Edma Seated in a Park, we find a secluded part of the park which has been chosen to allow the artist to work without too much interference from passers-by.