What a pretty cake!!! I love the design!!
This dollhouse trim is not the same, but you could use it to make a mold (e.g., Amazing Mold Putty) and turn it upside down. I think that's a rose:
Or maybe you could use this:
You could curve this into a swag before it (fondant, gumpaste) completely hardened:
AI like the last one that shanter posted. I like it better than the one on the cake. Looks more defined.