Hi,
No luck in the tree but this may help....
from free birth marriage death index...
http://www.freebmd.org.uk/cgi/search.plBirths Jun 1856
BLOOMFIELD Arthur Ipswich 4a 583
Births Mar 1861
BLOOMFIELD Emma Matilda Ipswich 4a 590
Births Sep 1862
BLOOMFIELD Walter Robert Ipswich 4a 566
Births Mar 1862
BLOOMFIELD Emma Elizabeth Ipswich 4a 550
and this...
Deaths Jun 1861
Bloomfield Emma Matilda Ipswich 4a 388
Using the General records office on line you can order copies of the above certificates which will confirm the parents names.
Walter Bloomfield was christened at St Clements, Ipswich...
Walter Bloomfield Christening: 28 NOV 1852 St Clements, Ipswich,
Parents: George Bloomfield and Mary Ann
This is from Familiy Search (IGI)
http://www.familysearch.org/eng/Search/frameset_search.aspThe others arent listed but it may be worth a direct enquiry to see especially as you say the elder 2 children were also baptised there - this would seem to indicate that possibly the ones in between were also.
However the proof of parents is on the certificates which
are registered so if its the proof you are after get a copy of the certificate.
Emma Alice is recorded under the birth marriage death index as follows....
Births Dec 1897
Bloomfield Emma Alice Ipswich 4a 927
Nelson appears as an incomplete name but as we have his twins details and there is no other Nelson it has to be him...
Births Dec 1897
Bloomfield Nelso_ George Ipswich 4a 927
again verification of parents can be obtained by getting a copt of the certificates.
I cant find a baptism record under IGI but not all churches are on there for Ipswich
Arthur George appears as follows....
Births Jun 1902
BLOOMFIELD Arthur George Ipswich 4a 1040
again no record on IGI but I personally find IGI better for earlier births
John Bloomfield comes up as (from IGI)
John Bloomfield Christening: 30 APR 1760 Playford, Suffolk, England
Parents: Daniel Bloomfield and Mrs Hannah Bloomfield
along with from the same parents....
Sarah Bloomfield Birth: 04 APR 1778 Playford, Suffolk, England
Daniel Bloomfield Christening: 17 AUG 1783 Playford, Suffolk, England
There are also duplicate records with the same parents with the surname spelling of
Blomfield which could indicate that prior to this the family may have been Blomfield (very common) and you may have to research Blomfield not Bloomfield to go further back or a mixture of both in the previous generation.
I should also mention that out of the 3 sets of records all mentioning the same family in 2 of the 3 records John has his birth as 1780 - this would fit in with he other 2 siblings better but isnt necessary a correct assumption.
There is only one marriage mentioned in IGI of a Hannah and Daniel before Sarahs birth date as follows...
Daniel Bloomfield Birth: About 1752 Of, Falkenham, Suffolk, England
Spouse: Hannah Chandler
Marriage: 27 JAN 1777 Walton, Suffolk, England
However although Walton and Falkenham are close they are not near Playford and although moving to Ipswich from Walton is logical as Playford seems quite rural I would have this as a very loose possibility unless Daniel maybe originally hailed from there (note it says 'of' Falkenham hence he wasnt necessarily born there)
and going back to rural locations you will most likely be looking at Blomfield surnames.
Hope that is of some help.
Yi