Right then, from the starting chain onwards:
As I understand it you join starting chain to form a circle, be careful not to twist the chain. (I always find this tricky).
Round 1: Work 3 chain (this counts as your first treble) then work one treble into the next five chain, miss a chain then one treble into each of the next six chain, continue until the round is complete and join with a slip stitch into the top of first chain 3.
Round 2: Chain 1, double crochet in next stitch, chain 1 miss next stitch double crochet in next stitch all round, join with a slip stitch in first chain 1.
Round 3: Chain 1 make 3 trebles in first one chain space, double crochet into next double crochet all the way round, join with a slip stitch in first chain 1.
Then follow the diagram A2.
Here's a photo of my sample, sorry it's a lurid pink but I hope it gives you some idea.
I've got another 'keen'... Ouch!