Q: My daughter has just got a note book but can't use my iTunes accoun as it says 5 devices already on the account how can I see what devices are on the account

The quote below is from Manage your associated devices in iTunes - Apple Support

If you need to remove some, the link above has instructions.

You can see the devices associated with your Apple ID in iTunes on your Mac or PC:

1. Click to open your account in iTunes, or use these steps:
   1. Open iTunes, choose Store > Sign In, then enter your Apple ID and password.
   2. Choose Store > View Account.
2. Click Manage Devices in the iTunes in the Cloud section. If you haven't associated any devices with your Apple ID, you won't see the Manage Devices section.

Next to each device, you can see when it associated with your Apple ID. You can also track how many days remain before you can associate your device with a different Apple ID.