Cheetahs are one of the most endangered species, notwithstanding their incredible speed over short distances. When the mother goes off to hunt, the youngsters are in greatest peril. Cheetahs often go for days without eating when game is not plentiful or the prevailing winds and camouflage are not in their favor.
In this case, the youngsters are little older, and may even have helped the mother in bringing down the unfortunate impala.