Она избежала проблемы.

Because the verb избежать takes the genitive case, not the accusative.

So Russian asks:

• избежать чего? = to avoid what?

That is why you get:

• проблема → nominative
• проблемы → genitive singular

This is something you usually just memorize with the verb:

• избежать проблемы = to avoid a problem / the problem
• избежать ошибки = to avoid a mistake
• избежать опасности = to avoid danger

So the key point is: избежать + genitive.

Избежала is the past tense, feminine singular form of the verb избежать.

Breakdown:

• избежать = infinitive, to avoid
• избежал = past masculine, he avoided
• избежала = past feminine, she avoided
• избежало = past neuter, it avoided
• избежали = past plural, they avoided

Since the subject is она (she), the verb appears in the feminine past form: избежала.

In the Russian past tense, verbs agree with the subject in gender and number.

With она (she), the verb takes the feminine ending:

• он избежал = he avoided
• она избежала = she avoided
• оно избежало = it avoided
• они избежали = they avoided

So the -а ending tells you the subject is feminine singular.

Избежала is perfective.

That matters because perfective verbs usually describe a completed action or a successful result. Here, the idea is that she managed to avoid the problem.

Compare:

• Она избежала проблемы.
  = She avoided the problem.
  → completed, result-focused

• Она избегала проблемы.
  = She was avoiding the problem / She kept avoiding the problem.
  → process, repeated behavior, or ongoing action

So in this sentence, the perfective form suggests a finished event.

They are an aspect pair:

• избежать = perfective
• избегать = imperfective

Use избежать when you mean a single completed avoidance:

• Она избежала проблемы.
  She avoided the problem.

Use избегать when you mean habit, repetition, or process:

• Она избегает проблем.
  She avoids problems.
• Она избегала этой темы.
  She was avoiding that topic / used to avoid that topic.

A useful shortcut:

• избежать = to manage to avoid
• избегать = to be avoiding / to avoid habitually

Yes, Russian can often omit subject pronouns when the meaning is clear from context.

So you could hear:

• Избежала проблемы.

However, there is an important detail: Russian past tense does not show person, only gender and number. So избежала by itself could mean:

• she avoided
• I avoided (if the speaker is female)

Because of that, она helps make the subject explicit.

So:

• Она избежала проблемы. = clearly she
• Избежала проблемы. = depends on context

It can mean either, depending on context.

Russian has no articles like a or the, so:

• Она избежала проблемы.

could mean:

• She avoided the problem
• She avoided a problem

Usually the surrounding context tells you which is more natural.

Also, in this sentence проблемы is genitive singular, not plural.

That can confuse learners because:

• nominative plural of проблема is also проблемы

But after избежать, the genitive is expected, so here it is understood as singular genitive.

Yes. Russian word order is flexible, and changing it usually changes emphasis, not the basic meaning.

Neutral order:

• Она избежала проблемы.

Other possible orders:

• Проблемы она избежала.
  Emphasis on the problem
• Она проблемы избежала.
  More marked; often used for contrast or emphasis

For a learner, the safest neutral version is:

• Она избежала проблемы.

A rough pronunciation guide is:

• Она → a-NA
• избежала → eez-bee-ZHA-la
• проблемы → pra-BLYE-my

Stress:

• она́
• избежа́ла
• пробле́мы

So the full sentence sounds roughly like:

a-NA eez-bee-ZHA-la pra-BLYE-my

Because избежать is perfective, it does not normally have a present-tense meaning like English avoids.

Instead:

• Она избегает проблемы / проблем.
  = She avoids the problem / problems.
  → imperfective present

Future with perfective:

• Она избежит проблемы.
  = She will avoid the problem.

Past completed:

• Она избежала проблемы.
  = She avoided the problem.

So the sentence you have is the past perfective form.