I am not sure if you have lots of information or are looking for more information or only living descendants 
 
 
Possible birth and baptism from IGI Extracted record
BEHENNA  James   
Birth  29 Nov 1821      
Baptism 9 Jan 1822  St James, Westminster, London ENG     
Father     Isaac  BEHENNA    
Mother     Mary Ann BREAY
A spelling variation with Ellen's surname on the marriage reg 

Marriages Dec 1843   
BEHENNA James Poole    Bloomsbury 1/   82     
MOLTON    Ellen Elizabeth  Bloomsbury1/82
1851 Census
Living at 14 Oval Street, St Mary's Lambeth    HO107/1873 
BEHENNA James  Head Married  29 years  Railway Clerk  b. St James Middlesex
BEHENNA Ellen  Wife Married  26 years    b. St James Middlesex
BEHENNA Mary Ann  Dau  8 years  Scholar  b. St Anns Middlesex
BEHENNA Ellen Elizabeth  7 years  Scholar  b. St Anns Middlesex
MOULTON Mary M.I.L  Wid 58 years  Dependant on her son  b. St Martins Middlesex
MOULTON Augustus  B.I.L. Wid  28 years  Carver & Gilder  b. Lambeth  Surrey
HIETT Hannah   Serv   17 years   Domestic servant    b. Henley  Oxfordshire
Their arrival in Victoria in August 1852 on the 
Mary Harrison  Port B Fiche 005  Page 008 and 007 for James.
POOLE James  30 years 
POOLE Ellen 27 years
POOLE Ellen 9  years   
POOLE Mary Ann 8 years
I guess you have found this
http://www.unisanet.unisa.edu.au/research/condon/teachers/Teachers.asp?TeacherID=1410So there are the following marriages and it is descendants from these marriages you are seeking 
 EVERETT
EVERETT Charles Ellis  Status not known 22 years  Father Charles EVERETT
POOLE Mary Ann 22 Status not known  Father James POOLE
8 Nov 1864-11-08
Place Christian Chapel Mitcham  Ade 60/45
and
HILL Nathaniel 23 years  Status single  Father John Victor HILL
POOLE Ellen E 24 years  Status single  Father James POOLE
13 Jul 1873
At the residence of Mr Broadfoot Thebarton    Yat 96/162 
A couple of deaths
POOLE James
25 Nov 1890  68 years   Status Not known  Relative Not recorded
Residence Adelaide   Died at Port Adelaide  PtA 190/86
POOLE Ellen Elizabeth
4 Aug 1903  78 years  Status Widow  Relative James Behenna POOL [Deceased husband]
Residence Parkside  Death Place Parkside  Ade 296/116
Hopefully a descendant will find your request.
Cheers
Cando