Well there are plenty of trains. The East Coast Mainline is faster but you can travel via the West Coast too. Here are some trains :

- Edinburgh Waverley - London Euston 06:52 - 12:54 direct

- Edinburgh Waverley - London Euston 08:52 - 14:54 direct

- Edinburgh Waverley - London Euston 10:52 - 16:54 direct

- Edinburgh Waverley - London Euston 12:52 - 18:54 direct

- Edinburgh Waverley - London Euston 14:52 - 20:55 direct

- or plenty of other trains via Glasgow Central or Preston (a bit faster)

Check for your travel date, there might be engineering works.

It might be good to book a free seat reservation on these busy mainlines on gwr.com (see advice here)

You can check train timetables on good planners like bahn.de or with the company running the train (Avanti West Coast)

Thank you for this information. Wow, I didn't realise how many train companies there are. I hope we can use our first class Eurail pass with all of them. I will check.

I see GWR runs through Preston. Thanks for the heads up about maintenance, looks like there's a lot. We're not travelling till the start of September so hope it'll be finished by then. Gee, it'll take me that long to learn about all the trains and routes! Really appreciate your advice.

Cheers

Jenny

GWR Great Western Railway doesnt operate at Preston The West Coast Mainline trains from Edinbrugh to London Euston are Avanti West Coast services A subcompany of Italian Railways (thanks to British Franchise Concept on mainline Routes ) 

Avanti offer in 1st class a comblimentary Meal service on their trains One of the best offers in my opinion :) 1st Class Menue on Avanti Services. 

The Website of GWR (Great Western Rail) is a good source to reserve seats as GWR Website make it possible to reserve most trains in the UK (and biggest advantage it´s even free ) 
Great Western Rail itself operate mainly trains from London Paddington to Penzance & South Wales (Cardiff, Swansea) 

GWR is the only UK consolidator for reservations for most operators, but it does in fact only operate trains from London to the South West. The Edinburgh to London (West Coast) service is operated by Avanti West Coast.

All long distance and most medium distance trains in the UK offer first class seating and many offer lounge facilities for first class pass holders (If you are travelling).

Great links again thank you.

I managed to call Avanti yesterday and was impressed by the people that answered. So good to be able to call and get an instant answer. I want to travel with Avanti - the good looks good too!

Eurail replied in email that our pass does cover Avanti which I wouldn't have known if not for a UK friend and you mentioning them. I think it v would have just been if they came up by chance in my train searches. It seems I can book Avanti on the phone with my pass information. I'm glad I have time to work this out but wish I could book further in advance than 8-12 weeks.

Really appreciate your help. It's quite a maze.

Cheers

Jenny

All trains in the UK are covered, no matter which company (except some steam railways ofc)

Don't worry, it's very unusual to be able to book train tickets more than 3 months in advance everywhere in Europe. Nobody will be able to book, regular tickets or pass users. It's very rare that a train sells out (+ reservations are optional so you can always board the train).

Remember that seat reservations in the UK are free so do not pay anything for them.

So glad I joined this forum. Feel much better informed. Thank you again.

Jenny