余る: food for two people and cloth for a possible pouch
Read the portions left after too much food was made and the possibility of making a small pouch with a little remaining cloth.
A leftover amount and another possible use
余る (あまる) means to remain or be left over. The food sentence states an amount for two people, while the cloth sentence states the possibility of making another item.
二人分 measures portions of food. 布が少し identifies a little remaining cloth. Keep the food quantity separate from a count of people who stayed, and distinguish what can be made from what was already made.
Overproduced food and a little remaining cloth
「料理を作りすぎて二人分余った。」 (I made too much food, leaving enough for two people.) Too much food was made, and enough for two people remained. 二人分 describes the amount of food rather than two people remaining in a place.
「布が少し余るので小さな袋も作れる。」 (A little cloth remains, so I can also make a small pouch.) The little cloth remaining makes a small pouch another possible item. 作れる expresses that possibility, without reporting a completed pouch.
What each surplus makes explicit
The food example gives the leftover portions after overproduction. The cloth example gives a material remainder and another item that can be made. Each describes its surplus in a different way.
Retain the stated bounds: enough food for two people and a little cloth. The sentences do not add a completed pouch or a separate intention behind leaving the food or cloth.
How are the surplus food and cloth presented in these 余る examples?
Show the answer and why
The food is an amount left for two people. The cloth is a small remainder that allows a small pouch to be made as well; the pouch is not reported as already completed.