A search for Adela Lejzorowicz turned up Adela Leizerowitsch, who was born in the right age range for the school she attended (she was born in 1931).
Zelig and Ruchla Leizerowitch both lived at the same two addresses as Adela, and Ruchla's occupation was listed as housewife. Zelig's was listed as 'Buwung,' and I have been unable to find a translation for that. In addition, they were both born in 1900, making them old enough to be Adela's parents.
Under Adela's and Ruchla's notes, they are listed as having been transported on September 9th, 1942. According to the Secondary Sources, there were deportations to Chelmno between September 5th and 12th, 1942. Based on these dates, I have concluded that she was probably murdered at Chelmno in gas vans.