В песочнице дочка сидела на земле, брала песок ладошкой и клала его в ведёрко.

Because after в meaning in, Russian usually uses the prepositional case when talking about location.

• песочница = sandbox
• prepositional singular: в песочнице = in the sandbox

So в песочнице answers where?

Compare:

• в песочнице = in the sandbox (location)
• в песочницу = into the sandbox (movement toward it)

Дочка is a common, natural word meaning daughter, often a little warmer or more everyday than дочь.

• дочь is the basic dictionary form
• дочка is a very common diminutive/colloquial form

In many real-life sentences, Russians prefer дочка because it sounds more natural and affectionate. It does not necessarily mean little daughter, but it often feels more personal.

All three are:

• past tense
• feminine singular
• imperfective

They agree with дочка, which is feminine singular.

So:

• сидела = was sitting / sat
• брала = was taking / took repeatedly
• клала = was putting / placed repeatedly

The feminine past ending here is -а:

• сидел (he sat)
• сидела (she sat)

Imperfective is used because the sentence describes an ongoing scene or repeated actions in progress.

The girl was:

• sitting,
• taking sand,
• putting it into a bucket.

This is more like a picture of what was happening, not a report of one completed action.

Compare:

• брала песок = she was taking / kept taking sand
• взяла песок = she took the sand (completed act)
• клала его в ведёрко = she was putting it into the bucket
• положила его в ведёрко = she put it into the bucket (completed)

So imperfective helps create a descriptive, continuous background scene.

Because на with location also takes the prepositional case.

• земля = ground, earth
• prepositional singular: на земле = on the ground

So:

• сидела на земле = was sitting on the ground

Again, this answers where?

Compare:

• на земле = on the ground (location)
• на землю = onto the ground (movement)

Because брала takes a direct object, so песок is in the accusative case.

• nominative: песок
• accusative: песок

For many inanimate masculine nouns, nominative and accusative look the same. So the form does not change, but the case function does.

Here:

• брала что? — песок

So it is accusative by function, even though it looks identical to nominative.

Ладошкой is the instrumental case of ладошка.

• ладошка = little palm / hand
• ладошкой = with her palm / using her palm

This instrumental form shows the means or instrument by which she took the sand.

So:

• брала песок ладошкой = she was taking sand with her palm

A more neutral word would be рукой = with her hand, but ладошкой sounds more vivid and childlike, which fits the sentence.

Его refers to песок.

• песок is masculine singular
• therefore the pronoun is его = it

So:

• клала его в ведёрко = was putting it into the bucket

Even though sand is a substance rather than a countable object, Russian still uses a singular pronoun to refer back to песок.

Because this is movement into the bucket, not location inside it.

With в:

• в + accusative = into
• в + prepositional = in

So:

• клала его в ведёрко = she was putting it into the bucket
• оно было в ведёрке = it was in the bucket

Here the bucket is the destination of the movement, so Russian uses the accusative.

Ведро means bucket.
Ведёрко is a diminutive form: little bucket, or simply a more affectionate/everyday way to say it.

In a sentence about a child in a sandbox, ведёрко sounds very natural, because children often have a small toy bucket.

So the diminutives in this sentence help create the scene:

• дочка
• ладошкой
• ведёрко

They make the sentence feel warm, concrete, and child-centered.

Russian does not need a separate word like English was in the past continuous.

Instead, the sense of was sitting, was taking, was putting comes from:

1. the past tense forms, and
2. the imperfective aspect.

So the sequence

• сидела
• брала
• клала

naturally gives the meaning of an ongoing past scene.

The conjunction и simply links the actions:

• she was sitting on the ground,
• taking sand with her palm,
• and putting it into the bucket.

Yes. Russian word order is flexible, because cases show grammatical relationships.

The given order is natural for descriptive narration: В песочнице дочка сидела на земле, брала песок ладошкой и клала его в ведёрко.

It starts with the setting:

• В песочнице = In the sandbox

Then introduces the subject:

• дочка

Then describes what she was doing.

You could change the word order for emphasis, for example:

• Дочка сидела в песочнице на земле...
• Песок дочка брала ладошкой...

But the original sounds smooth and story-like.

Because the sentence lists several past actions performed by the same subject:

• сидела на земле
• брала песок ладошкой
• и клала его в ведёрко

Russian commonly separates such coordinated predicates with commas when appropriate, just as English does in a series. The comma after земле separates the first action from the following ones.

So the structure is basically:

• she sat on the ground,
• took sand with her palm,
• and put it into the bucket.

Yes, it is natural, especially in a descriptive or literary context.

It paints a visual picture: the girl is scooping up sand with her palm. The use of ладошкой makes the image more childlike and vivid than a more neutral phrase like:

• брала песок рукой

So this wording is not just grammatically correct; it is stylistically expressive as well.