Sen, I see there are a few warnings and advice for Holkham beach, eg. see this article which followed a family getting stranded and needing rescuing there.

We once took Misty for a walk from Cley beach towards Blakeney Point. It was a nice quiet walk but it is one where I think checking the tide tables and planning is advisable. It would be possible to get cut off by the tide coming in quickly and behind you Blakeney side.