Whats the general consensus for switching out Racial Tool Proficiencies?

I don't have a lot of energy to write so to make the long story short: My character doesn't fit any of the Dwarf proficiencies for tools (mason, brewers, smiths) because she would not have done any of that stuff in her past. I reluctantly chose Smith's Tools. However, she was a skinner. I recently found out that skinners have the leatherworker proficiency in d&d (I'm new to the game, I didn't know that was possible which is why I added it to my back story.) Whats the general consensus for switching one of those tool proficiencies for Leatherworking proficiency? Just asking before I run it by my DM cause I feel like i've asked so much already

EDIT: I forgot to mention an important point: the game has already started, we're level 3 at this point but I have never used my smith's tools proficiency (mostly because I haven't had enough money to even buy smith's tools.)