I'm 5'2", normally 120lbs-ish. I love the size of the Mahala, have this exact bag!
I think it looks great on you.
I had the same issue with the Ramona, thought it was too big, got a Riki, then ended up with the Ramona... wait, TWO Ramonas LOL.
I have briefly owned a Maddy before and it was too small for me.
KEEP IT!!! IT LOOKS GREAT!!!