triplets brilliant news about DH !
How about somewhere in South Devon ,near Dartmouth or Totnes ?
You might be able to find somewhere available ( thinking holiday rental ) in a small village and use it as a base . Maybe Kingsbridge ? Strete village ?
Totnes is medieval town interesting in itself ,but is bit like a hippie campus - lots of crystal and fairy shops which I think early female teens like .
Lovely market ,Elizabeathan themed once a week .
Dartmouth is great for pottering ,beautiful boat trips up the Dart ,Agatha Christies house at Greenaways ,crab fishing at Dartmouth and Dittisham .
Blackpool sands is a private beach ( if any sun ! ) or Beesands is lovely - miles of beach ,grass football pitch ,toilets ,pub and cafe .
Torcross ,Slapton ?
Trips to Dartmoor ,Buckfastleigh Abbey .
Salcombe for boats .
Good luck ,I find booking holidays really hard ...