nah, she only gives you recipes you havent learned, once you have them all she just gives you star fragments but you can get duplicates if you just dont learn them. This is correct. Thus, if you learn each recipe immediately after receiving, you will never receive a duplicate.
Does Celeste give DIY to visitors?
If a friend happens to have Celeste visiting their island on a given night, you may also visit them and speak to her for a recipe of your own – however, you can only receive one recipe from her per day.
How many DIYS can you get from Celeste in one day?
You can only get 1 DIY from Celeste per day, even if you run into her in multiple towns.