Can you suggest ideas to celebrate DD 18th birthday, please.

[Sunshineandswimming]

She is 18 at the end of this month and she wants to do something, but not sure what! She has autism and although we've visited cities like London, Leeds & York, she's not keen on the noise & chaos.
She likes the beach & the countryside - calmer places to visit. She likes nature, sunsets & eating out and is gluten free. She has a boyfriend who would like to come with us.
We live in the East Midlands & can easily get to Norfolk, Suffolk, Derbyshire, Nottinghamshire & South Yorkshire.
I'm looking for something for a long weekend (Fri - Sun) or a day out. I don't want to spend a fortune and the coastal cottages I've looked at are £600+ for the 2 nights (for 2 bedrooms).
Any ideas or suggestions - I realise that the criteria is rather limited (especially budget).
Thanks.

Hathersage in the Peak District? Pubs to stay/eat in, decent restaurant (Bank House), nice cafes (Open House and the Deli). Walks along the various edges, down Padley Gorge etc.

Would you consider Wales? I’ve stayed in North Wales and there are some beautiful beaches and lots of activities.

@MargotJane thank you - The Bank House menu does look good!

@IggyAce are you able to share the recommendations, please? My daughter really likes Wales & we're looking for different places to explore maybe in a longer holiday. Thank you.

Ask her.

Sorry- 'Ask her' was an easy answer.
If she knew exactly what she wanted, you wouldn't be asking.
NORTHUMBERLAND COAST.

@StrongandNorthern 😆 Yes, she doesn't know either.

Thank you - Northumberland coast does look nice & we haven't been there before.

@Sunshineandswimming my favourite beach was Newborough National Nature Reserve and Forest, we went in August and went on an evening so it was quieter as it’s very popular. Probably not a concern in jan/feb but something to consider if you go later.
There are great selection of National trust properties.
I’ve stayed in both Caernarfon and Beddgelert both of the properties we stayed in wouldn’t work for your group. But both places were lovely and had a good selection of pubs cafes. Caernarfon is closer to the coast.
The picture is Newborough at low tide when you can walk over to the island.

Can also recommended Northumberland coast, bamburgh is beautiful and the walk from Craister to dunstanburgh castle is nice. There are also boat trips from Seahouses to see the Puffins.

£400 is the minimum you are likely to be able to find if it’s decent. Definitely look at the Yorkshire coast or ne, lovely spots. Stayed in Staithes recently which might be suitable

(We stayed at the pub at the top of the hill)

Thank you @IggyAce I will take a look.
@miamo12 yes, Staithes does look nice. Thanks.