You noted that Regina Elfer was Aron’s Wife and she died after having a baby sometime after 2/5/1866
I am a descendant of them, and her Hebrew name was Rifka רבקה and she passed on ט' אייר תרמ"ח which is Friday, 20 April 1888
Here is a link to a picture of her מציבה
https://drive.google.com/file/d/1a-Vi3moG5oBIZ78HsH3zBTctXOceJIRS/v...
