We disciplined from day one pretty much.

If she has her feet on the table, tell her no, we don't put our feet on the table & put them down like you are already. If she hits, tell her no it's not nice to hit etc. Make sure you explain everything to her. She may not understand at this age, but she will learn if you are consistent. Explain that mummy & daddy don't put their feet on the table do they? Then PRAISE!! A LOT!! Tell her how good she is for sitting nicely, that she has lovely manners etc.