Here is a letter written by Mrs Hawthorne. Turns out that Maria Louisa Hawthorne went by the name of Louisa in family circles:
CONCORD, Friday morning, July 30, 1852.
MY DEAREST MOTHER,--This morning we received the shocking intelligence that Louisa Hawthorne was lost in the destruction of the steamer "Henry Clay" on the Hudson, on Wednesday afternoon, July 27. She has been at Saratoga Springs and with Mr. Dike for a fortnight, and was returning by way of New York, and we expected her here for a long visit. It is difficult to realize such a sudden disaster. The news came in an appalling way. I was at the toilet-table in my chamber, before seven o'elock, when the railroad coach drove up. I was astonished to see Mr. Pike get out. He left us on Monday morning,--two days ago. It struck to my heart that he had come to inform us of some accident. I knew how impossible it was for him to leave his affairs. I called from the window, "Welcome, Mr. Pike!" He glanced up, but did not see me nor smile. I said, "Go to the western piazza, for the front door is locked." I continued to dress my hair, and it was a considerable time before I went down. When I did, there was no Mr. Pike. "Where is Mr. Pike?--I must then have seen his spirit," said I. But upon going to the piazza, there he stood unaccountably, without endeavoring to enter. Mr. Hawthorne opened the door with the strange feeling that he should grasp a hand of air. I was by his side. Mr. Pike, without a smile, deeply flushed, seemed even then not in his former body. "Your sister Louisa is dead!" I thought he meant that his own sister was dead, for she also is called Louisa. "What! Louisa?" I asked. "Yes." "What was the matter?" "She was drowned." "Where?" "On the Hudson, in the 'Henry Clay'!" He then came in, and my husband shut himself in his study.
We were about sitting down to breakfast. We sat down. Una was in the bathroom; I went to tell her. This upset me completely. I began to weep. By and by Mr. Pike got up from the breakfast-table, and said that unless he could do something for us, he must immediately return, and he went out. At last, my mind left the terrible contemplation of Louisa's last agony and fright, and imaged her supremely happy with her mother in another world. For she was always inconsolable for her mother, and never could be really happy away from her. So I burst out, "Oh, I have thought of something beautiful, sornething that will really comfort us!" Una's face lightened, but Julian could not pay heed. But I bent over him and said, "Aunt Louisa is with her mother, and is happy to be with her. Let us think of her spirit in another world." A smile shone in his eyes for a moment, but another flood of tears immediately followed. All at once he got up and went to the study,--he had the intention of consoling his father with that idea; but his father had gone on the hill.
Mr. Hawthorne will ask his sister Elizabeth to come here, to change the scene. It is an unmitigated loss to Elizabeth. Tell my sister Elizabeth not to stop here as she had intended. Mr. Pike said that Mrs. Dike was almost distracted,--he never saw any body so distressed. The news came by telegraph,--"Maria is lost." Mr. Pike brought us the paper. Good-by.
Your affectionate child, SOPHIA