I find two things weird about this. 1. The large one's face is almost square, not rounded "puff!" like
2. The mother is agitated but the young ones are still sleeping and not afraid.
With no doubt, hypnotics was added into the food for the kos.
"Mama~ Reimu is sleepy~ Mister sleepiness meets Reimu easy~ Reimu is sleeping!"
"Zzz... Reimu can'ch each mishter sweet-sweet anymor..." The smaller ko was in a god dream. How could they lose their alertness so easily?
"Stupid big sis quickly prepare mister soft-soft for the cute ittle ones! Little ones are sleeping easy! Doesn't Yu-house exist for us Yukkuri?!"
"Sure; but how about you, Reimu? Little ones fall asleep, aren't you tired? Wanna have some more mister sweet-sweet while letting little ones to sleep in the room?"