Hi Sandra,
I've tried various combinations with the last set of links with no success.
(I'm also using Firefox.)
Do you think that this link you provided earlier (which we cannot open) may have additional information contained therein?
(
https://familysearch.org/search/collection/2001148)
My original thoughts were that if her birth was missed during the original transcription, a manual search in the DC offices may prove worthwhile.
I have the family in DC in the 1875 Washington City Directory ( Matheson, Daniel,lab.h D nr 13th se), and as the directories were usually compiled mid-way through the previous year, I thought it would be feasible that she would have been born in DC. They were in various properties within DC until the mother died in 1879 at 319-4th se.