Thanks for the reply, Gleno1.
If I recall correctly, you're travelling to London to visit someone in Lansdowne Care Home but a member of your party has difficulty with steps. The nearest 'step-free' Underground station to the care home is Kilburn, on the Jubilee Line. It's about a mile away but the 189 bus runs from the station along Claremont Road, passing the care home.
However that won't help you much unless you can access the Victoria Line via a route with very few (if any) steps. If you're still staying in the Kings Cross area, your route would have to be by taking the Metropolitan Line from Kings Cross/St Pancras to Finchley Road and then changing to the Jubiliee Line for the one stop to Kilburn:
http://www.tfl.gov.uk...ee-tube-guide-map.pdf
Alternatively you could stay at the Black Lion in Kilburn. It's reasonably close to the Tube station and the 189 bus runs past its front door:
http://www.lodging-wo...est+house.121318.html
Chris