In these straight-laced early Victorian/Regency times it was very inconvenient, not to mention against society’s convention, to be found with a gentleman, alone and unescorted.
Society’s Doyennes then insisted on a marriage. And so it happened with the Duke and Katherine. They were compromised and thus forced into a marriage neither intended.
Katherine especially intended never to marry. She was far too familiar with the result of marriage – that is children! And before that childbirth.
Her aunt, with whom she lived, acted as a midwife to the poor of her husband’ s parish and Katherine often accompanied her. She saw how many women suffered in childbirth and what was notable was that death in relation to childbirth was mostly in fit young women who had been quite well before becoming pregnant.
See http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1633559- According to this article in the Journal of the Royal Society of Medicine. Puerperal pyrexiai (fever) was a common cause of mothers’ deaths – an infection caused by the insanitary conditions of childbirth. At least 55 women per 1000 per year, died during childbirth between 1800 and 1850. Other medical issues were placenta praevia, placenta abruption and postpartum haemorrhage additionally convulsions related to eclampsia were also found.
Added to this were the high child death rates – in poor populations it was often 20% mostly in the age range 0-5 years.
[Interesting point here, some cultures don’t name children officially until they have passed a certain designated age from one month in some, to one year in others - this being the result of the high death rate and the feeling that an unnamed child was not really considered a part of the family].
You need to remember the high incidence of disease and its ease of transmission in poor urban areas added to poor sanitation giving infant diarrhea as a cause of death also.
So with this experience you can well see why Katherine would not want to marry and especially not to have children. And ways to prevent pregnancy were as yet uncommon and far from reliable.
But marriage it was - for both of them - and thereby followed a learning journey for them both about each other and about their own personalities and emotions.