I believe so. Its small yet it also stretches and the mits were meant for a younger baby bc they dont have any thumbs to mess with, similar to a scratch mit! Hope this helps!
Yes, I think it would still fit nicely at 6 months! :) My daughter had so many little hat and mit sets like this that i cant remember what age she actually wore each one, if at all but just from looking at it, i believe it would fit! :) Hope this helps!