This family gets a little more confusing and it appears obvious that some of the information in the Census is incorrect!
For example:-
1871 Census Sithney
Emma PEARCE, head, widow, 49, housekeeper, St Hilary, Deaf
William John do., widower, 28, tin and copper miner, St Erth
Edwin do., son, unm, 25, tin and copper miner, St Erth
Alfred do., son, unm, 22, tin and copper miner, Illogan
Elizabeth
Anne do., daur, unm, 15, mine labourer at surface, Breage
Richard do., son, unm, 13, mine labourer at surface, Breage
Anne do., daur, 8, scholar, Sithney
Edwin PEARCE, g'son, 3, scholar, Helston
Unusual to have a daughter named Elizabeth Anne as well as a daughter named Ann!
But it gets a little more confusing when checking birth/baptism records.
William John bp. 19th June 1842 St Erth - residence Kirton Wood
Henry bp. 11th April 1844 Crowan - residence Crowan
Although Edwin was apparently born at St Erth it seems likely he was baptised at Illogan where the next three children (Emma, Simon and Alfred) were born. I don't have records for Illogan for that period but then these children are not really the problem.
It is these baptisms at Sithney that are creating the dilemma:-
Thomas James bp. 5th June 1863 Sithney
Richard bp. 5th June 1863 Sithney age 5 years
Mary Elizabeth bp. 5th June 1863 Sithney
Elizabeth Ann bp. 5th June 1863 Sithney
All are recorded as child of Simon and Emma Pearce of Church Town but it is interesting/strange that Richard is the only one to whom an age is affixed especially when the 1861 and 1871 Census show that Elizabeth Ann was born about 1855 or 1856.
Thomas James was buried at Sithney just a couple of weeks later on June 21st 1863 at the age of 1 and FreeBMD shows his birth was registered in the September Qtr of 1862.
Elizabeth was age 5 in 1861 and then in 1861 is recorded as Elizabeth Ann age 15 which would indicate that 'Ann' is probably Mary Elizabeth.
But also confusing is that Mary Elizabeth appears to have been possibly registered as Elizabeth Mary.
And as Emma appears to be gone before 1881 there is no family group to refer to which makes it a little difficult to find this child and verify her name.
CT