Vegetable fields represent chores within the family.
The big river represents the distance and contradiction between people.
How to bring back three fish represents how to bring back a good attitude and a good relationship.
Red water represents the sadness caused by everyone's discord, that is, the blood in the heart; At the same time, your mother also realized that blood is thicker than water.
Your mother is thinking about how to get the fish back. If you don't bring it back with water, the fish will die. I guess here that the water in your mother's dream represents money, so it means that if you don't take some money back to grandma, it will be difficult to get along well. This is my guess.
Then he dreamed that I was arguing with a man in that vegetable field. I went to him in tears. He asked me what happened to that man and then helped me solve the problem. This dream is a dream that she hopes someone can mediate between herself and her grandmother.