Got a quick response:
I understand your concern that you would like to buy a kindle book to gift for your sister.

Please be informed that kindle content cannot be given as a gift on Amazon.co.uk at this time. While gifting Kindle content is not yet offered in the Amazon.co.uk Kindle store, we are working to make it available in the near future. In this case, I have let the Kindle team know that you're interested in gifting kindle content.

Customer feedback like yours helps us continue to improve the service we provide, and we are glad you took time to write to us.
( The Light in Chains don't touch the Pope's boner, Sat 17 Dec 2011, 9:56, 1 reply, 14 years ago)

So that's me screwed then
I suspect a gift certificate is the way forward - a bit disappointing really.

However I have just had a bacon and egg butty so it's not all bad.
( The Light in Chains don't touch the Pope's boner, Sat 17 Dec 2011, 9:57, Reply)