Gender: girl
School:
School #8B
Searching 'Mira' and 'Slodkiewicz' under all the search parameters, I came up with only two results. Of those two, only one was born in the birthdate range to have made her the appropriate age to have signed the album.
I found two relatives living with Mira--Fajga Ruchla (b.1840, perhaps a grandmother) and Laijb (b. 1923, perhaps a brother or older cousin.)
They were all transported on March 15, 1942, on which date there was a transport to Chelmno, and I have determined that this is likely where they met their fate.