I'm a local resident. I'd book via a Rothbury firm, they may be able to take it all in as a single transaction since they'll be more keen on the business. In that respect it may be better to reverse the trip, stay in Rothbury, visit Cragside, then go to Alnwick. For Alnmouth to Alnwick, if you aren't in a rush you could call on arrival, there may be a taxi at the station, if not one of the several Alnwick companies could get a taxi there in 10 minutes. If you are a book reader, don't forget to plan a trip to Barter Books.

https://www.pottstaxi.co.uk/

There are buses between Alnwick and Rothbury (number 15), for those looking at this thread in the future, every few hours, and they run past Cragside. There is a better service between Rothbury and Morpeth, which also has a train service (X14)

Paging [MENTION=184556]Stez[/MENTION].