I think Rebecca will do a fine job in business. She has the concept of haggling right down,although she is still a bit hasty with her counter offers, prior to doing the maths. An example:
"OK Rebecca, if you eat four more bites you can leave the table."
"No, five more bites!"
"OK love, you win. Five more bites. Now eat up."
Everyone happy with the outcome. Long may it last.