I just don’t get it...

Not really sure where to post this, but it has to do with my daughter’s name so here it goes.. I named my daughter Kassie, like Cassie but with a K and all her life(she’s 5) many people have mistakenly called her Casey, and it really bothers me. When I named her, I never thought anyone would look at her name and think Casey. I mean I only changed one letter. My sister also wonders how people mix it up so easily. Am I wrong for being bothered my this? I’m curious. How did you read her name when you first saw it?