To back out of my visiting guest's day trip?

[TheVanguardSix]

Not nail-bitingly interesting but I need some advice on etiquette here.

One of my BFFs from childhood is coming over from the States in August. She'll stay 3 nights with me here in London before heading off to do a trip across Europe. She'll be with her 11 year old son who is dying to go to Pooh Corner/Ashdown Forest.

I don't drive at all but my friend is dying to go to the Ashdown Forest and have cream tea at the café there. So I agreed that we (my 3 kids- probably just 2 because my eldest is SO not interested) would go by train and then bus to the forest. I just looked up the trip and it's full on. I live in West London- Hounslow. I'd have to go to Victoria, get the train down to East Grinstead then take a bus into the woods...Or taxi. My 3 year old is a poor traveller and is probably on the spectrum for Autism so my worry is that a 2 1/2 hour journey from start to finish would just be way too much for him. DH works full time and won't be able to take the day off to babysit and I don't want to leave DS with a sitter or friend for what will likely be 8 hours.

Would you consider me a lame friend for suggesting to my dear friend that she and her son go off by themselves? She's a seasoned globe trotter, so I wouldn't worry about her ability to get herself down there on her own steam.

I'm more worried that I'm being a lousy friend.

I'd be amazed if an 11 year old wanted to go to Pooh Corner! I suspect it is your friend who wants to go and I'd just wave as you pack them off on their own.

Surely it's just a wood and afternoon tea.

That's fine. Just say it's too much for 3yo and you don't want to spoil it for 11yo.

Make sure you have obviously planned suitable activities/visits and catering for the rest of their visit and wave them off with a smile.

Aww you're not being a lousy friend OP! :) It's completely understandable that it would be very difficult for you to make the journey. Have you discussed this with your friend at all? I'm sure she'd understand totally :) And you're already doing her a lovely favour by putting her up for a few nights while she visits as well.

Nope wave them off!

Incidentally I can imagine the mirror post from friend:

I'm staying with DFriend and her DC for just a few days at the start of a European tour. DS and I really want to do a particular day out near her house, but I don't think it's very suitable for her (much younger) DC. WIBhorriblyU to go anyway? She says we should go without them but is that really ok?

Unanimous response: YWNBU. Have a great time with DS and pay your hosts lots of attention before and after.

I just wanted to let you know that we did this recently and it would be very difficult to do by public transport. The Pooh Corner shop where the cafe is is in the village of Hartfield and then the walk the the pooh sticks bridge is a short drive or a walk of at least 30-40 minutes.

It's definitely not an easy one with little people with you.

This is the information sheet with map

Oh thank you all so very much! I've been feeling terribly guilty about the possibility of backing out. But just reading about the fact that the café is a 30-40 minute walk from the forest is enough to make me truly realise how tough the day would be.
Thanks a million for all of your very helpful input!