Where to put a child seat in a C

I have a 29' Class C, with the normal side facing sofa, 3 seat belted positions, None with shoulder harness, and 2 belted positions at the dinette, which I don't think is safe, as her legs will be jammed into the table, I'm thinking of placing the child ( booster seat eligible in Va.)in the forward position on the sofa.
The only position with a shoulder strap, (beside the driver) is the front passenger seat, not legal for her to be in.
Question is, what's everyone else do?