How long does it take for a malnourished cat to recover?

My sister rescued a cat that was severely malnourised yesterday. We found her collapsed in the middle of the road. She was so weak she couldnt stand. Since then she has been giving her kitten milk, water, and soft cat food. She can walk around but shes still pretty unstable. Problem is that she hasnt made a bowel movement of any sort yet. Its been over 24 hrs now. We lack the money to take her to the vet so shes just doing the best she can with what she has. The cat also acts like she cant see close up. Does anyone have any insight into this matter? SERIOUS answers please!!!!