"Will you keep it down?! I am trying to use the quill!"
"I'm telling mob!"
Constance Flynn-Fletcher is an ancestor of the modern-day Flynn-Fletcher family and a look-alike of Candace. She is the disapproving governess of two young scientists, Dr. Phineastein and Ferbgor. Her relationship with Dr. Phineastein is currently unknown but they might have been closely related. She bears a striking resemblance to Candace Flynn in word and deed, writing in typical modern teen slang about her crush Jeremiah and ratting on the young scientists to an angry mob. She appears to have been the object of Jeremiah's affections before she was turned into a monster in a quite accidental turn of events under the accountability of Jekyll Doofenshmirtz's machine.
Nothing is known on her whereabouts after the angry mob subsequently misidentified and pursued her.
Her personal behavior and attitude is very similar to that of modern day Candace Flynn. She is obsessed with exposing the antics of Dr. Phineastein and Ferbgor to an angry mob the same way Candace is with getting Phineas and Ferb in trouble with Linda.
Apart from that, she writes and sends out letters as excessively as Candace talks over the phone. Both share the use of modern teenage slang when they communicate. Furthermore, she fantasizes over a boy she falls in love with, Jeremiah and stalks him in a manner reminiscent to the way Candace does with Jeremy.
As mentioned above, as of the era she is shown, she bears a nearly uncanny resemblance to Candace Flynn, including her body shape and her face. However, she wears her hair in a bun as opposed to her modern-day counterpart, who lets it hang freely.
Along with that is her apparel, which reflects her era.