You asked "Is there a common reason why a woman doesn't seem to exist prior to being married?"
In her case, if she was married at age 17, then there would be few records on her becase she was a child.
Even if she were older, more records did apply mainly to men: property, military, voting, naturalization, occupational records such as guilds or apprenticeships, legal cases, etc. etc.
For girls, I can think of: birth, baptism, church membership or confirmation, census, school records (not likely to have survived til now), guardianship records (if one or more parents died), wills/probate (if included in an older relatives records)...
She was probably listed on a passenger list, but I think those early years are scarce and contain little information.
I think your best bet would be later records: obituary, death certificate, church records, newspaper articles, local histories, etc.