Hmm no idea, going off 1911 census which is closest information I have around this date, possible families were as follows:
Charles (age 56) - Stockman on farm - Walton on Naze
Benjamin (26), Bertha (24) - Police Constable - Southend on sea
Other possible males around age are all in the Navy and unmarried which seems less likely. So I am thinking the two on the left are Benjamin and Bertha. With the older gentlemen on Bertha's right possible being Benjamin's father Charles. No clue on fourth fellow though. And then could be wrong on all counts.
Does the fellow on the far left look anything like a police constable to back this up, if there is anything about his attire that is revealing of this?
Find attached a picture of Charles taken about 10 years prior if anyone is good at matching faces, they look reasonably similar to me.