RIGHT!! I got a picture book of Frozen Fever for Christmas. To quote the page (note I'm in the UK so it might vary from a copy you might find) 'Everyone sang 'Happy Birthday', then Kristoff slid down Sven's antlers and knelt before Anna with her birthday cake. Anna had a huge smile on her face.' NOTHING about declarations of romantic feelings, but the cake is clearly mentioned!
Though honestly, Frozen is actually full of declarations of all different kinds of love.
That's one of the many reasons why I love it so much. Frozen isn't afraid to love.