Hi Helen. Welcome to justanswer.
Have you installed the drivers on your Macbook air? Which version of OSX is installed in it?
The versions are 10.5,10.6,10.7,10.8,10.9,10.10,10.11 etc
CLICK HERE and this link will automatically detect the OS version. Once done, then download the Full Driver package and once the download is complete, then open it and follow the on-screen instructions. If you get any error then reply so that I can guide you through.
Alternatively, you can choose for Secure Remote Assistance and I will install the necessary software on both of your device.
Hi Helen, just checking in. How did things turn out?