"What happened to Katarina and her three daughters after they entered the United States is a mystery."
My reading of the landing card says she never entered the US.
Note the following: - at the top of the card is written "BSI." That stands for Board of Special Inquiry. Even though she indicates this is a day trip, Immigration Service was not about to let her into the country because . . . - on the back of the card is written "LPC - no passport." Immigration officials believed that coming to the US with three children and no husband, she was likely to become a public charge if she overstayed her 1-day visit. - at the bottom of the card is stamped DEBARRED. She was refused admittance tothe US.
There is also an accompanying ststistical sheet for the crossings at Niagara Falls for that time period. Note lines 8-11. This is Katraina and the children. The title of the list is "Non-statistical Debarred," further proof that she did not enter the US.