Dagmar has the same facial structure as Arianna Jalowitz, a local maid. She can easily be cloned in Create a Sim with debugging mode on. Often going unnoticed, Dagmar has 22 personality points, instead of the usual 25.
She is mostly interested in weather, travel, and work. While Dagmar hasn't maximized any of her skills, she is close to maximizing the body skill, and is well on the way towards maximizing the creativity skill. She shares her name with a mail carrier from Pleasantview, though there isn't any evidence that the two of them are related.
Do NOT attempt to add Dagmar to a household, make her selectable, or tamper with her in any way or form. Doing so will corrupt the neighborhood she is in.