Zerin, there is usually a way to exclude alcohol where Rose calls for it in her recipes. As Julie notes, a little experimentation is what’s needed. Rose herself took a cake almost based on Grand Marnier and redesigned it for her many fans who don’t use alcohol for one reason or another. The result was the recipe of which she is most proud in the new book - her Golden Lemon Almond Cake!
Happily, a quick review of more traditional sticky toffee pudding recipes reveals that the switch to a non-alcoholic version is simple. Use boiling water in place of the beer. Pour it over the pitted dates. Add about 2 tsp of coffee essence along with the baking soda, and I would think you could add the vanilla at the same time. Set aside to cool, and then continue with the recipe as written.
p.s. Perhaps our UK members will be able to add to or correct my suggestion in some way? And welcome to the forum, btw. We’re happy that you have joined us.