Can I Add Gelatin to French Style Mousse?

Hi friends, first time posting! I’m going to a dinner party tomorrow night and I offered to bring a dessert. I’m making a Bailey’s chocolate mousse, it’s done French style so I whip egg whites for the main thickener but no matter how much I whip them I feel like the finished product never comes out as thick as it should. I was wondering if it’s possible to add gelatin to the recipe to work as a thickener and if so how what would be the best way to do so?

My current thought process would be to bloom the gelatin in the heavy cream before I bring that and the baileys to a boil on the stove. The entire mixture would then be poured over chocolate and, in line with the original recipe, I add butter and an egg yolk before adding that whole mixture to the whipped egg whites. Will doing that mess up the whole recipe? Is there a better way to thicken it? Any help would be appreciated!