As is common in many species the mother's instinct is to protect her child from harm.

The child's instinct is to get away because "Geez mum, you're embarrassing me in front of all the other gorillas!"

I'm not David Attenborough so I can't be certain, but I suspect that this is the female which was born in January last year as per the following press release:

A tiny female Western Lowland Gorilla has been born at Taronga Zoo.

Born to experienced mother 'Kriba' on Saturday 15 January, the youngster has been named 'Kipenzi' which means 'precious one' in Swahili.