Here are some easy ways to help your dear mother in the household work -
Keep your place clean and tidy- Don't make your room a mess, keep it clean and tidy by keeping your books, toys, clothes ,shoes  and other stuff at it's place. Do not throw the bits of paper, food wrappers etc on the floor. Your mom will feel very relaxed to see your room neat and clean. 
Water the plants- Watering the plants is not very difficult. It is a very nice and enjoyable activity. The best part of it is that by doing this you can take a closer look of nature too.
Fill the water bottles-In summers a lot of water is needed for drinking.It becomes very difficult for your mom to provide cool water for the whole family but anyhow she does it. You can help her by filling the water bottles. Every time when you see an empty water bottle fill it and keep it in the fridge.
Set the table for dinner- Setting the table for dinner is fun and not so difficult at all. When your mother is ready to serve the dinner you can lay the table, you will surely enjoy it. Don't forget to keep your plates in the sink when you have finished eating.
Help her in dusting the furniture- Dusting the furniture is a very time taking work. It will not be possible for you to dust everyday but you can help her in dusting on Sundays or on other holidays. 
Hang out the washed clothes- Older kids can help their mom in the laundry work by hanging the clothes outside. It will take just a few minutes. 
So these are a few easy ways to help your mother at home to make her  household duties easy for her. You will feel so good to see a much relaxed and happy mom.