What happened to Kate?

One big mystery concerning The Man’s family tree is that of his great grandmother’s “disappearance”.

Catherine Eliza Pagett Bown, Kate, was born in Leicester around 1861 to Henry Pagett Bown and Ann Blakesley.  Henry and Ann had at least four other children, John William (1848 -1923), Samuel Henry (1851-1889), Thomas Pagett (1853-1916), Arthur Garrad (1855-1875) and Annie (1866).

She appeared to have a normal life with her family until her marriage, aged 24, to James Davidson.  They married on 25th October 1885 at St Mathews Parish Church, Leicester.  Over the next 6 years Kate, and James, had three children, Wallace Henry (1886-1954), Stuart James (1888), and Maggie (1891).
In 1891 Kate was living in Bilston, Staffordshire with her husband, James and sons, Wallace and Stuart (later known as James).  This census is the last record I have been able to find thus far that relates to Kate.

Ten years later, in 1901, James was living in Wellingborough, Northamptonshire with an Elizabeth Davidson named as his wife.  Elizabeth, born as Elizabeth Deane, had a son, Tom Sutherland, born in 1894 in Small Heath, Warwickshire.
James and Elizabeth had four children by 1901, Donald Cory (1896), Olga Madge (1897), Laura Mildred (1899) and Nelly (1900).  Another child, Dorothy (1893), is with the family but a birth registration has not been located yet.
The 1911 census shows the family living in Newport, Monmouthshire with the older children and their latest additions, Enid (1904), Alan (1906), Vernon (1909) and May (1910).  James and Elizabeth claim to have been married for 18 years (they didn’t actually tie the knot until 1934) which would put the start of their relationship around 1893.  The year after Dorothy was born.  However, Elizabeth’s possibly illegitimate son, Tom, was born in 1894, after the supposed start of the relationship.
Did they simply say 18 years to make Tom seem like a child of their relationship?  (Tom married in Newport as Tom Sutherland Dean Davidson.)  Or was James really Tom’s father?

James’ first wife, Kate, “disappeared” between 1891 and 1895.  Was Kate Dorothy’s mother?
Through a descendant of James and Elizabeth I have been told that the family story was that Kate had gone “doo-lally” (forgive the political incorrectness) and was admitted to a Lunatic Asylum.

What really happened to Kate though?  If, as the family stories say, she went “doo-lally” then what was the reason for her illness?  Where were they living when she was admitted into the asylum?
I have a theory that could answer the first question… While searching for asylums in (and around) the families last known place of residence (Dorothy was allegedly born in Wolverhampton) I came across a comment by someone who had a relative admitted to an asylum for Puerperal Fever, a common but widely misunderstood infection resulting from improper hygiene (on the Doctor’s part) during childbirth.  This made me curious and on further reading I discovered a condition called Puerperal Insanity, or Puerperal Psychosis as it is now called.  Puerperal Psychosis, which has a close link with Bipolar Disorder, occurs within the first month after childbirth, and was the cause of hundreds of women killing their children during the 1800’s.

This leads on to the if’s……
If Dorothy was the product of James and Kate’s marriage then is it possible that Kate’s ‘madness’ could have actually been Puerperal Insanity?  A condition which, had she been suffering from now, could be treated effectively.
Patients in an asylum were recorded on census returns using just the person’s initial which really isn’t helpful in locating Kate.  A marriage or death record for Kate Davidson has not been located even using different variations of her names.

Throwing in another spanner, why did James and Elizabeth wait until 1934 to get married, he was 76 years old by then and the couple had been living together as husband and wife for 40 years and had nine children who were adults themselves.  Was it simply that James didn’t want to be a bigamist and waited until Kate died?  This is purely speculation as without a death there is no proof.

What happened to Kate? Why are there no records of her?  Where should I go from here?  This question will burn for as long as it takes to solve it.