I've been a parent almost 5 years and I can't believe I didn't think of this until now.
Last night I was serving Josie some pizza and was fumbling with the knife, infomercial style, trying to create bite-sized pieces when inspiration struck: just use kitchen shears. I did and it worked like a charm! All you need are food grade kitchen or chef shears.
I'm totally doing this with all her food from now on.