Her mum now could be jailed over the death

A “JEALOUS” girl allegedly killed her newborn baby sister by hurling the tot out of a fourth floor window 40ft up.

The five-year-old is said to have been home alone with the 21-day-old when the horror plunge happened in Vasilyevo, Russia.

Her mum had reportedly left her alone with the baby girl while her husband was at work.

Passersby heard a girl screaming from a fourth floor window, then saw the motionless baby on the ground.

Witnesses said their “knees went weak” at the horrific sight.

Paramedics confirmed the 21-day-old’s death at the scene after falling onto the concrete.

“A criminal case has been opened over the death of the infant,” said the Russian Investigative Committee.

Potentially, the mother could face a jail sentence.

Investigators are examining whether the five-year-old was “jealous” of the new baby.

One report said her mum was visiting a friend at the timee she was left alone.