I saw this motif on another lady's blog (apologies I can't find the blog again at the moment) and thought it looked so pretty I went on the search for the booklet. Luckily I found it for a couple of dollars on Amazon. The booklet is entitled "Tatting by Penelope - Book 3". I only think it's a bit of a shame that these little booklets have no author or date of publication.
I tatted this in Anchor Liana, a ball of thread I found hiding away at the bottom of a craft bag in the attic. I had previously used this to crochet (many years ago!). I find this is now discontinued - shame, as it's a great thread for tatting.
I didn't realise quite how large this would turn out: it measures 5 ½ inches from point to point when tatted with size 20 thread. A lovely design.