Sue: Following are particulars I’ve managed to locate re dates/places of birth:

1. Sophia Jane Richardson:
born 16 March 1840 Marylebone, London, England (Free BMD)

1850 Galveston census
Richardson, Sophia J./F/11/England

(married Simon Jackson Stookey 1866)

1870 US census (Morgan, Illinois)
Stookey, Sophia/39/F/W/At Home/England

2. Annie Richardson:
born Sep 1841, London (Free BMD)

1850 Galveston census
Richardson, Annie/9/F/England

3. Louisa Richardson:

1850 Galveston census
Richardson, Louisa/6/F/England

1860 Galveston census
Richardson, Louisa/12/F/Texas[sic] NOTE: Error in transcription - should read England

4. David Richardson:

1850 Galveston census
Richardson, David/7/M/England

1860 Galveston census
David Richardson/15/M/Texas[sic] NOTE: Error in transcription - should read England

5. Eliza Richardson:

born 26 Sep 1847 (IGI)
St. George, Douglas, Isle of Man, England
Parents: Father: David RICHARDSON
Mother: Elizabeth OATES

1850 Galveston census
Richardson, Eliza/4/F/Isle of Man

As well, the ship’s manifest list dated 1848/05/09 for vessel “Waldron”, arriving through Castle Gardens, New York includes:

David Richardson/Merchant/29/England
Eliza Richardson/25/England
Sophia Richardson/10/England
Anna Richardson/8/England
David Richardson/6/England
Louisa Richardson/4/England
Eliza Richardson/Infant/England

The 1860 Galveston census entries showing Louisa and David's place of birth as Texas are obvious mis-transcriptions as they were both born prior to the family's entrance into the US in 1848. The handwriting on the original census form is suspect as well.

Thank you again for all your help.