The young lady—for youth had revealed its presence in her buoyant bound up the bank—walked along the top instead of descending inside, and came to the corner where the fire was burning. One reason for the permanence of the blaze was now manifest: the fuel consisted of hard pieces of wood, cleft and sawn—the knotty boles of old thorn trees which grew in twos and threes about the hillsides. A yet unconsumed pile of these lay in the inner angle of the bank; and from this corner the upturned face of a little boy greeted her eyes. He was dilatorily throwing up a piece of wood into the fire every now and then, a business which seemed to have engaged him a considerable part of the evening, for his face was somewhat weary.
This paragraph is one that connect Eustacia to the wilderness. Firstly, Hardy has her buoyantly bounding up the bank and striding across its height, symbolic of both strength like the great outdoors and an superior power over the wilderness she conquers. Secondly, she comes face to face with the burning bonfire, which she herself set, and flinches not. This represents her own natural strength--strength like the great outdoors--that quenches even the natural danger of fire.