When: 1970, 1998 or '99
Googled: "northwest territories changing birth certificate", but I really have no idea how to phrase this properly
This is about a fandom character, but is only for my own personal head-fanon, not for a story or anything.
The character in question, who is only known by her married name in canon, was born in 1970 to parents whose spouses had both recently died. She was probably brought up to believe she was the posthumous daughter of her mother's husband (who'd actually died at least four months prior to her conception).
Regardless of whose name was put in the "father's name" field (I think either the mother's dead husband, or - if she thought someone would catch on to the discrepancy or had a crisis of conscience - nothing at all), I figure this character was given her mother's surname at the time of the child's birth, which was almost certainly still her dead husband's last name.
In 1998 or '99, when we actually meet this character in canon, during the course of the episode she learns who her actual biological father is.
Now, after all that, my question. After providing proof of her newfound paternity (timing evidence, DNA tests with canon half-brother, etc.), would this character be able to change the surname on her birth certificate from to match her bio dad's? I know, with proof, she could probably correct whose name, if any, is on the "father's name" field. But she wouldn't want to give up her married name to legally change her surname to her bio dad's, so that leaves just the birth certificate.
I suspect the answer is "no", she wouldn't be able to change the surname, but it never hurts to ask.