I'm a bit overwhelmed by all the responses so far.
1. Yes I have both William Norman & Eliza Norman's death entries and Emily Harriett Norman is listed as living on both (Eliza died in 1878 at Beechworth & William in 1881 in Melbourne), their daughter Fanny is listed as dead and she died on Malta.
2. Jessie Norman did marry David Wood (the photographer in South Melbourne) as Judith rightly found out, Jessie Wood died in 1930 in Melbourne and is buried in the Boroondara cemetery, I have her death certificate but of course it's no help.
3. Strange that there are several other birth records with same parents names but I definitely know that Emily was born at Valletta Malta from family records but there is also an excellent British family history site dedicated to Malta that lists all the Norman births correctly and match the death certificates of William & Eliza
http://website.lineone.net/~aldosliema/residents4.htm,
http://website.lineone.net/~stephaniebidmead/other%20sites.htm4. I have checked Trove but there is no mention (at least what the OCR routine has picked up) of an Emily Norman marriage that fits in the range 1857 - 1900.
5. The clue still seems to be the witness to William Norman's (Emily's brother) marriage to Catherine McKinley at Beechworth in 1871 where one witness is Emily H Weir.
6. Her Brother William and sister Jessie Wood's lives are fairly well documented but there is no mention of their sister in any newspaper notices.
7. There are several Normans' in South Australia and in particular an Emily Norman who was born almost in the same year as Emily Harriett Norman who marries a William Knightly in 1866, an excellent match except on Ancestry there are two public family trees that detail William Knightly and this Emily Norman was born in Cambridgeshire around 1846 - 1847 which matches the FreeBDM entry so not the right Emily.
Thanks for all the help so far.