OK, for anyone new to this thread, this is the brief:
OP is spending a day in London with a friend who she hasn't seen for 2 years and is looking for suggestions for brunch (10am) and afternoon tea (around 3pm, finish by 6pm), in Central London. Budget is £25 per person, for each meal. Comfortable and calm places. OP isn't very familiar with London.
OP is arriving in London the day before (Kings Cross station) and spending the night in a hotel (originally Westminster area but is open to staying in Kings Cross area instead). Friend is coming into Waterloo on the day itself.
IMPORTANT: OP walks with two crutches so can't do too much walking and would like sit-down opportunities during the day. Friend is happy to travel across London to meet OP.
So, having looked at the locations of the two possible hotels (Premier Inn Hub in Westminster and Kings Cross) I would stick with the Westminster option as it's a more interesting part of London, sightseeing wise. It's close to Parliament Square (tick Big Ben, although is it still covered in scaffolding?), the Thames, Whitehall, St James' Park, Buckingham Palace etc. I don't know what distances you can cover on foot so Google Maps/Streetview is your friend here. The Kings Cross location is OK but you'd need to travel into the centre to see any sights, and it seems a shame not to have them on your doorstep for such a short visit.
For brunch I would suggest the area north of Trafalgar Square (Charing Cross Road and St Martin's Lane) - you can get there by bus.
(I was going to suggest the restaurant/cafe at the National Gallery but it doesn't look like it's open.)
St Martin's Lane options (all restaurants so probably more spacious than the cafes):
Cote www.cote.co.uk/restaurant/st-martins-lane/menus/a%20la%20carte/?category=january-specials
Browns www.browns-restaurants.co.uk/restaurants/london/covent-garden
Dishoom (Indian, people rave about it) www.dishoom.com/covent-garden/
Charing Cross Road options (cafes, so probably more busy):
Patisserie Valerie (called the Leicester Square branch) - www.patisserie-valerie.co.uk/pages/patisserie-finder
Ole & Steen (Danish bakery) - oleandsteen.co.uk/
Some of those could be either brunch or afternoon tea, but you might not want to spend the whole day in that area. Maybe you could walk to St James Park, or book a (free) ticket for the National Gallery (indoors, seating and access to toilets!). Or just meandering - it's close to Covent Garden, Leicester Square, China Town etc. Or you could get a bus or tube if you want to go further (use a contactless payment card to travel on public transport).
Will you have an overnight bag with you or do you need to return to the hotel to collect it? If the former you could have brunch in one area and then travel close to Kings Cross for afternoon tea, although I'm not sure if many of the eateries in that area are geared up for afternoon tea.
Does anyone have suggestions for inexpensive afternoon tea (max £25 per person, doesn't have to be a package) in the Kings Cross area, that doesn't involve lots of walking?