I agree absolutely with all the other ladies here; if you like it, wear it! Shoulders back, walk tall and you'll look fantastic! (Now I need to follow my own advice!)
I bought a KS last week with Bloomies friends and family. if you love it rock it. She makes a great everyday quality handbag and it seems we are close in age.
I have the cobblehill devin mini. The cobblehill devin is a bit bigger. I do not think it is a "childish bag". Especially the darker colour ones that look quite elegant. I saw a black one on the website recently I think.