Стоит ей открыть альбом, как она сразу ищет кисточку и акварель.

This is a fixed Russian pattern meaning as soon as..., the moment..., or it only takes ... for ... to happen.

So:

Стоит ей открыть альбом, как она сразу ищет кисточку и акварель.

means something like:

• As soon as she opens the album, she immediately looks for a brush and watercolors.
• The moment she opens the album, she immediately starts looking for a brush and watercolor paint.

A very literal breakdown would be something like:

• It only takes her to open the album, and she immediately looks for a brush and watercolor.

That literal version sounds unnatural in English, but it helps show how the Russian structure works.

No, these are very different.

1. Ей стоит открыть альбом

This means She should open the album or It would be worth her opening the album.

Here стоит means it is worth / one should.

2. Стоит ей открыть альбом, как...

This is the special pattern meaning as soon as she opens the album...

So word order matters a lot here.

• Ей стоит открыть альбом. = She should open the album.
• Стоит ей открыть альбом, как... = As soon as she opens the album...

This is one of the most important things to notice in the sentence.

Because in this construction, the person who performs the infinitive is usually put in the dative.

Pattern:

Стоит + dative + infinitive, как ...

Examples:

• Стоит мне выйти, как начинается дождь.
  As soon as I go out, it starts raining.
• Стоит ему заговорить, как все смеются.
  As soon as he starts talking, everyone laughs.

So in your sentence:

• ей = dative of она
• открыть = infinitive

Together: стоит ей открыть = as soon as she opens

Открыть is perfective, and that fits this construction well because it refers to a single completed action: opening the album.

In стоит кому-то + infinitive, как..., Russian often uses a perfective infinitive when the meaning is the moment someone does X.

So:

• открыть = to open (once, completed action)
• открывать = to be opening / to open repeatedly / to open in general

Here the idea is:

• first she opens the album,
• immediately after that she starts looking for the painting materials.

So открыть is the natural choice.

In this pattern, как introduces the second event that happens immediately afterward.

Structure:

Стоит + dative + infinitive, как + main clause

So:

• Стоит ей открыть альбом, как...
• As soon as she opens the album, ...

This как does not simply mean basic how here. It is part of the whole construction.

You can think of the sentence as having two linked parts:

1. Стоит ей открыть альбом
2. как она сразу ищет кисточку и акварель

Together they mean that the second action follows the first one right away.

Yes, they refer to the same person.

• ей is used in the first part because the construction requires the dative
• она is used in the second part because she is the normal subject of the main clause

So the grammar changes because the two clauses have different structures:

First clause

Стоит ей открыть альбом
The construction uses dative + infinitive

Second clause

она сразу ищет кисточку и акварель
Normal clause with a subject in the nominative

This is completely normal in Russian.

Because the sentence describes what she typically does whenever that situation happens.

Russian often uses the present tense for:

• habitual actions
• repeated behavior
• vivid narrative

So она сразу ищет means:

• she immediately looks for
• she immediately starts looking for

The imperfective искать is natural because the focus is on the process/activity of searching, not on successfully finding the items.

If Russian wanted to emphasize finding something, it might use найти or another verb, but here the meaning is about the action she begins right away.

Most naturally, it sounds habitual or characteristic.

It suggests something like:

• every time she opens the album, she immediately looks for her painting tools
• this is her usual reaction

That is because of the combination of:

• the general trigger pattern стоит... как...
• the present tense ищет
• the adverb сразу

So the sentence feels like a description of her normal behavior.

Альбом is the direct object of открыть, so it is in the accusative case.

For masculine inanimate nouns like альбом, the accusative singular is the same as the nominative singular:

• nominative: альбом
• accusative: альбом

So even though the form does not change, the case is still accusative because of its role in the sentence.

Кисточку is the accusative singular of кисточка.

Meaning

Кисточка usually means brush, and in this context it means a paintbrush.

Form

Because it is a direct object of ищет, it is in the accusative:

• nominative: кисточка
• accusative: кисточку

Also, кисточка is a diminutive form. Compared with кисть, it can sound a bit more everyday, concrete, or affectionate depending on context. In many contexts, especially with art materials, кисточка is very natural.

Here акварель most likely means watercolor paint or watercolors.

It can refer to:

• watercolor as a medium
• watercolor paints
• sometimes even a watercolor painting, depending on context

In this sentence, since she is looking for a brush and watercolor, it clearly means the painting material.

As for the form: акварель is a feminine noun, but in the singular its nominative and accusative are often the same in form:

• nominative: акварель
• accusative: акварель

So it stays unchanged here even though it is a direct object.

Сразу means immediately, right away, or at once.

The sentence already implies quick succession because of стоит... как..., but сразу strengthens that idea. It emphasizes that the second action happens without delay.

So the feeling is:

• she opens the album
• and right away she starts looking for the brush and watercolor

Without сразу, the sentence would still mean something close to as soon as, but сразу makes the immediacy even clearer.

Yes, it is common and very useful.

The стоит... как... pattern is normal Russian and appears in both speech and writing. It can sound slightly more polished or literary than a very plain как только sentence, but it is not strange or overly formal.

For comparison:

• Как только она открывает альбом, она сразу ищет кисточку и акварель.
• Стоит ей открыть альбом, как она сразу ищет кисточку и акварель.

Both are natural. The version with стоит... как... often feels a bit more expressive and compact.

Yes. You can often hear:

Стоит ей только открыть альбом, как она сразу ищет кисточку и акварель.

or

Стоит только ей открыть альбом, как...

This adds the sense of all she has to do is open the album... / the very moment she opens the album...

So только is optional, but it makes the trigger feel even more immediate or minimal.

Without только, the original sentence is already completely correct and natural.