We know that she filled 1/3 of the container before using 4L to fill it the rest of the way. This means that 4L = 2/3 of the bucket. Therefore, we now know that the bucket can hold 6L. The problem states that she fills the bucket. Now we just need to convert the liters to milliliters.

And there is your answer! I hope this helped! If so, please leave a thanks. Have a blessed day!