Bewick House is on Front Street in Newbiggin by the Sea. It's a three-storey terraced house, so there are stairs. It's about a thirty second walk to the steps down to the beach.
It sleeps five. Three bedrooms, one bathroom. It's got a 4 Star rating. It's comfortable and clean. The WiFi works fine. There's a washing machine and parking for one car on the driveway.
The beach is sandy and the promenade is good for a flat walk. The village has what you need: a Co-op supermarket, a good bakery, a couple of pubs that do food, and some takeaways. There's an ice cream parlour on the promenade.
You can bring one dog. The back yard is small and enclosed, but it's handy for letting the dog out.
For days out, you're well placed. Druridge Bay is about a ten minute drive south for a long beach. Morpeth is twenty minutes inland for proper shops and supermarkets. Alnwick Castle and Gardens are about forty minutes north. The Holy Island causeway is just over an hour, but check the tide times.
Useful links if you're planning: Druridge Bay Country Park, National Trust Northumbria, and Northumberland Coast AONB.