No, you cannot transfer the Avios for free - unless you are GOLD.

You can see their points within your balance, and you can use them, but to take ownership of their points, you would need to transfer them in.

I had a similar issue when trying to book QR flights with mine and my partner's Avios. It was a nightmare even though we are both Gold, so just ended up booking the flights on BA.com for the QR award flight.