The recipe you alter becomes yours through the same act someone else might call losing the original.

Changing a recipe is simultaneously making it yours and losing the original, and which description applies depends entirely on who is speaking. The person who adapts is claiming ownership; the person who inherited the earlier version is watching something disappear. Both accounts describe the same act accurately.

This tension runs through everything handed down. When you alter a practice, a tradition, or a way a family does things, expect that someone will experience the change as loss even if your version is better. Neither of you is wrong. Acknowledging that openly costs very little and prevents the argument from becoming about whether the change was allowed.