Day 1: >>London Visitor Centre at Trafalgar Square - collect HOHO tickets
Hop On Hop Off Tour - Yellow Route
Natural History Museum
Albert & Victoria Museum (if we can manage...)<<

None of this day is good IMO. I'd forget about the H-o-H-o. If you do that you won't have time for much else that day. Plus it is very expensive. The 2 museums are near each other. But indoor/time-intensive museums are usually not a good idea on arrival day - jet lag and museums don't go together.

Day 2 - The Palace isn't open for tours in May.

Day 3 ->>Buckingham Palace Changing of the Guard Walk (free with HOHO tickets)
Thames River Cruise (free with HOHO tickets)<<

this is your THIRD straight day to the same area. (Day 1 on the H-o-H-o, Day 2, Day 3)

The changing of the Guard is free for EVERYONE so you don't need to pay for the H-o-H-o to see it. Walking is also free The Changing of the Guard is a HUGE time commitment -you must be there very early and can't really move for about 3 hours.

There are many boat tour options, none of which are expensive. IMO not really worth paying for the H-o-H-o just to get a boat ride which you can take on your own.

Here's what i'd change:

day 3 (saturday): tower of london (morning), borough market (lunch) and possibly St Pauls (city of london in general)-- a walk after lunch
evening at Trafalgar square, concert at St Martin in the Fields, walk down to the South bank and the london eye

Day 4 (sunday): british museum, shopping, covent garden

Albert & Victoria---Victoria and Albert

Changing of the guard is free with HOBO. and for the rest of the population lots of standing around with loads of other tourists, you would do better doing just about anything than this. Why not go and find Peter Pan's statue and then the Diana memorial while you walk in the park.

I have not heard much postive about HOHO bus tours - often cheaper and more personalized on your own. Day 1 sitting on a bus and two museums with jet lag may not be a good idea.

I second what janisj said - tower of London and boroughs market

I wouldn't do more than one museum a day. I agree with one of the notes above. I'd swap out a museum to take your daughter to Princess Diana's park at Kensington gardens. Should be so nice in June.

Also, add some tea breaks. Any child would love to go to Hamley's, the oldest toy store in London--it's near Picadilly circus.

I would go to the rose garden in Hyde Park. I think you can rent bicycles so you could see more of the park.

Peter Pan just across the lawn http://golondon.about.com/od/londonforfree/ss/Peter_Pan.htm

Oh wow... no one seems keen on Changing of the Guard and I really did not realise it would take 3 hours! Perhaps it isn't a great idea esp with an 8 yr old girl.

Oh no... I totally overlooked that Buckingham Palace isn't open in May/June. So it seems like there's not much point heading to the Palace then?

I'll definitely head to Kensington Gardens then seeing that the girl adores the Duchess - "Can we meet Kate Middleton when we go to London Mummy?" Yeah, sure, we'll just drop in for tea and scones

@bilboburgler of course I totally meant V&A! LOL!

@ssachida thank you for the suggestion, I'll definitely include that in.

Thank you for the suggestions! Back to the drawing board then.

re the Changing of the Guard: It doesn't take 3 hours . . . but you need to be there at least an hour early - and much earlier if it is a nice day or a weekend. Once you arrive, you need to stake out your little bit of sidewalk/pavement and can't really move until the performance/Guard change is over. So 2.5 to 3 hours total. And short people (your daughter) can't see anything at all unless they get there early enough to claim the best spots.

@janisj Aaah, got it... doesn't seem worthwhile now. Thank you so much!

While you can't tour the palace you can see the royal carriages.

<< I totally overlooked that Buckingham Palace isn't open in May/June. So it seems like there's not much point heading to the Palace then?>>

Well, you can walk by and look like so many tourists do every day. It's not like any major cities in North America have an enormous palace hard against a nice stretch of parks. I've been to London a bunch of times and never considered going inside the palace but have always wandered by just because - oh look! big flippin' palace!

The Changing of the Guard has been a bit of a joke for ages. I remember seeing it in 1987 and the band played show tunes and The A Team theme. Seriously. At that point, we left.

Is daughter a Harry Potter fan or still too young? If so, she may be rewriting about 1/2 of the itinerary anyway . . .

@BigRuss the A-Team? Really? That's hilarious! I'd expected a bit more pomp and ceremony to be honest.

Nope, not a HP fan so we'll give that a miss

It IS pomp and circumstance. The band can and does play anything, military marches, classical mainstays, musical theatre show stoppers, Beatles, movie theme songs . . . anything.

The only problem is the time it takes and the crowds