1 pound because she has 12 pounds right now, then on Monday she has 12-4=8. On Tuesday she has 8-3=5. Then on Wednesday, she has 5*3=15. Then on Thursday, she has 15/5=3. Then on Friday, she has 3-3=0. Then on Saturday, she has 0+1=1. So on Sunday, she has 1 pound left.