One or more Mary Ann Fages?

In the spirit of continuing to explore the lives of brothers and sisters of my direct ancestors, I have tried to find out more about the siblings of my great-great-grandfather John William (known as William John) FAGE, son of Jem (James) and Sarah (nee Wiltshire) FAGE.

Their first child was Mary Ann, who was christened on 2 April 1871 (census night) in Sandy, Bedfordshire and appears in the 1871 census aged 8 months. So she would have been born in September 1870. By 1881, her age is given as 5 and by 1891 she is shown as 15. So perhaps Mary Ann b.1870 died between 1871-1881 and a second child was named after her, born some five years later. This seems to be the case as there is a death index entry (FreeBMD) for a Mary Ann FAGE aged 1 in the September quarter of 1871, in the Biggleswade district.

There is a FreeBMD birth entry for the June quarter of 1876 in Biggleswade for a Mary Ann Fage. 

Mary Ann was a witness at her brother's wedding in 1893. By 1901, Mary Ann appears to have left the family home. A Mrs A BAKER is listed as one of WJ Fage's sisters at the time of his death in 1940 and there is a marriage entry for Albert J BARKER and Mary Ann FAGE in 1895, Biggleswade.

So hopefully this resolves the apparent census age discrepancy.