IIRC Britain goverment was pro French and Victoria had symphaties for Prussia. This, but more the speed of the1 German Victory kept Britain out of the war. But lets assume that Victoria is dead and Britain sides with France (Bismarck would have known) it means that the war of 1870/71 is butterflied away (and German unification delayed). France would still be considered the strongest nation ON the continent, so France might even look for allies against Germany - Maybe they can persuade Austria and Italy (the latter might be baited by the Papal state) Give France 2-3 years and Austria might have recovered enough from the German war to think of a "revenge" Venice might be gone, but what about Silesia