I don't know if the term 'spinster' in 1841 was any different from the term 'spinster' in the 21st Century. I was married in 1984 and as I had not been married before the term 'spinster' is on my marriage certificate. I have all my limbs etc!! I think broadly speaking the term 'spinster' is just one that means the fact that the woman is unmarried at the time of the marriage, the same as a man is termed 'bachelor' if he is unmarried.