Many thanks to everyone for all for your help. Stupidly I failed to mention Eliza had been married before to John Stallard and would possibly have been married as Eliza Stallard not Eckhardt, but I am not convinced Joe & Eliza ever did marry.
First daughter Birth Certificate 
Susannah Myers
registered 30th July 1858 Melbourne
Born Eleventh July 1858 4 

 Off Queensbury Street, North Melbourne, 
Father Joseph Myers age 25 born England,  Cab Driver
Married 1857 Melbourne
Mother Eliza Myers formerly Echard age 24 born Sydney
Second daughter Birth Certificate
Sarah Jane Myers
Registered 16th July 1860 Inglewood
Born 22nd June 1860 Inglewood
Father Joseph Myers  age 27 Cab Proprietor born Leeds, Yorkshire
Married July 4th 1857 Melbourne
Mother Eliza Myers formerly Eckhartd age 29 born Sidney (as recorded)
There appears to have also been a son
Joseph James Myers b. abt 1863 possibly Australia or New Zealand
He died 16th March 1876 age 13
A newspaper report states
Myers.- On the 16th of March, at the residence of D.Ross, Broadway, Reefton, after a long and painful illness, Joseph James Myers, (the youngest son of Mrs Cato.)
Death registration
Registration Number   Family Name   Given Name(s)        Date of Birth/Age at Death   
1876/4834            Myers       Joseph James                13Y-    New Zealand
Eliza also married Peter Cato (possibly called Peter Thomas Cato) in New Zealand 1869 
1869/6654 Eliza Stallard  Peter Cato
Eliza had 3 children to John Stallard
Maltravers Paul Stallard b. abt 1848
Maria Stallard b. 1850 Adelaide married Donald Ross 03 Mar 1866 Hokitika, Westland, New Zealand
Helen/Ellen Stallard b. 1853 Sydney married John Dick 29 May 1870 St John's Church, Westport, New Zealand
Joseph Myers snr, Paul Stallard & John Dick travelled to New Zealand together in 1862
Family Name Given Name Age  Ship Name Month Year  Destination Film_Mth Film_Yr Page
MYERS            JOSEPH 28  NORWESTER SEP 1862  PORT CHALMERS SEP 1862    010
STALLARD       PAUL    20   NORWESTER SEP 1862  PORT CHALMERS SEP 1862    011 (wrong age?)
DICK              JOHN    25   NORWESTER  SEP 1862  PORT CHALMERS SEP 1862   
I have lots of information about the family in New Zealand found at Papers Past
Joseph appears to have returned to Inglewood, Victoria Australia and got himself into trouble over a cab fare, when there was an argument about payment and he assaulted a woman. He was jailed for 6 weeks. See The Argus (Melbourne, Vic) Monday 13 Dec 1875, page 6 Trove Newspaper archives. (Several other newspaper clips to be found about this incident)
I am convinced this is my relative Joseph Myers who returned to England 
Family Name Given Name Age  Ship Name Month Year  Destination Film_Mth Film_Yr Page
MYERS JOSEPH                  44    KENT        AUG     1877 LONDON             AUG 1877 009
Joseph returned to being a Butcher in Leeds and married Rachel Senior in 1879. He had emmigrated to Australia with his brother Samuel in 1853 on the Earl of Charlemont, and was shipwrecked on arrival at Barwon Heads, Victoria. Lots of information found on this incident.
I believe his brother Sam might have died in Australia about 1874. His mothers name was Susannah and his sister Sarah Jane!
Just to note  John Dick and Paul/Thomas Cato appear to have been butchers too.
I was hoping to find a marriage certificate to confirm the connection of my Joseph Myers to Eliza and her family - I am sure they are the same!