The 1841 census with Rebecca Lemon, a Catherine, Samuel, Lemon and two not known's in Bell Lane, Spitalfields...
Well, in the same place on the 1851 there is a family of not known's all born Holland! Just a thought, Samuel had already left home by then as had Lemon so there are a couple of extra people which I can't account for and 2 children born Portsea and London who I am at a loss to explain, its a little difficult given the lack of info! There isn't even a mark in 'relationship'... why on earth are they down as not known? It seems the likeliest match to me!