How do I make jeet ignore first child?

I need to have two columns of posts in wordpress, apart from the first; that has to span both cols at the top. I've tried using $offset, but as the docs a VERY vague it's not working.

I can use first-child to set its width to 100% but the second post then still aligns to the right ... screwing up the flow.

How would I achieve this with jeet?