Depicted Evstafevna Yulia Kustodieva, the artist's wife with son, "my firstborn Cyril." (https://arthive.com/artists/1059~Boris_Mikhailovich_Kustodiev/works/380646~Morning_Depicted_Evstafevna_Yulia_Kustodieva_the_artists_wife_with_son_my_firstborn_Cyril)