By now the apartment is clean! My brother and my father installed the blinds although the one in Little One's room was deemed unsafe and detached again. The srew anchors haven't enough hold because the wall lacks sturdiness. We will try it with longer screw anchors, at a later time. The bath has now a cabinet so that things aren't just lying around anymore.
My visitors left in the evening to return home. That saddened the Little One who went at one time out of the appartment - he can reach the door handles now - to look if grandpa would come back. (I'm glad that we will visit them for the Easter holidays.) He had no hunger at all this evening and I worry over him; I hope he won't become sick.