SEAMARK, Hemel Hempstead, Early 20th century
It is not clear from you question how much you have already found out about your great-grandmother - but if you have not already obtained information from the online census returns, etc., you will find demonstration examples of how to do this in the Tutorial, which is there to get beginners started.
At the time of the 1901 census Joseph Saunders, an 83 year old retired farmer and miller, was living at 61 Marlowes and Margaret Seamark (described as single, 48, born Luton) was a trained resident nurse. Also in the house were Joseph's sister and a niece. The property was close to the hospital and the immediate neighbours were a surgeon and a retired surgeon. (For full details see Ancestry).
As you say, the 1902 Kelly's directory for Hertfordshire shows that Margaret Seamark ran apartments at that address. (The directory only listed well-to-do people or tradesmen, and would not list residents in apartments.) Margaret was probably listed because Joseph had died and either:
It could well be worth your while finding out if Joseph died in 1901/1 (from the death registration indexes) and if so get a copy of his will - which may indicate whether he left anything to his nurse.
I will be interest to know what you find out.
There is a web page for Hemel Hempstead
If you can add to the information given above tell me.
Page created August 2006