После прогулки у неё немного болела щиколотка.

Because после always requires the genitive case.

• прогулка = nominative singular
• прогулки = genitive singular

So:

• после прогулки = after the walk / after a walk

This is a fixed grammar rule: whenever you use после, the next noun goes into the genitive.

It means after the walk or after a walk.

A few useful notes:

• после = after
• прогулка = walk, stroll
• после прогулки can refer to a specific walk already understood from context, even though Russian has no articles like the or a

So depending on context, English might translate it as:

• After the walk
• After a walk
• After going for a walk

This is a very common Russian pattern, especially with physical states, pain, or possession involving body parts.

• у неё literally means at her or by her
• in this sentence, it functions like she had or her ... was hurting

So:

• У неё болела щиколотка = Her ankle hurt
• more literally: At her, the ankle was hurting

Russian often prefers this structure with body parts instead of a direct possessive like её щиколотка.

Compare:

• У неё болела щиколотка = natural, idiomatic
• Её щиколотка болела = possible, but less neutral in many contexts

Because у requires the genitive case.

The pronoun changes like this:

• она = she
• её = her
• after many prepositions, Russian uses the form неё
• so: у неё

This н- appears in forms of personal pronouns after prepositions:

• у неё
• к нему
• с ними

So у неё is the correct form after у.

Because щиколотка is the grammatical subject of the sentence.

The verb болела agrees with щиколотка, not with неё.

Structure:

• у неё = the person experiencing the pain
• щиколотка = the thing that hurt
• болела = verb agreeing with щиколотка

That is why you get:

• щиколотка болела
• not щиколотку болела

If it were accusative, it would usually suggest a direct object, but here ankle is not the object—it is the subject.

Because it agrees with щиколотка, which is:

• feminine
• singular

In the past tense, Russian verbs show gender and number:

• болел = masculine singular
• болела = feminine singular
• болело = neuter singular
• болели = plural

Since щиколотка is feminine, the verb must be болела.

This is about aspect and meaning.

• болела (imperfective) = was hurting / hurt / ached
• заболела (perfective) = started to hurt / began hurting

So:

• После прогулки у неё немного болела щиколотка = after the walk, her ankle hurt a little
• После прогулки у неё немного заболела щиколотка = after the walk, her ankle started to hurt a little

The sentence you have describes the pain as a state, not the moment it began.

Немного means a little, slightly, or somewhat.

It softens the statement:

• болела щиколотка = the ankle hurt
• немного болела щиколотка = the ankle hurt a little

So it suggests mild pain, not severe pain.

In English, you might translate it as:

• her ankle hurt a little
• her ankle was slightly sore
• her ankle ached a bit

Russian word order is more flexible than English, but different orders can sound more natural depending on emphasis.

The given sentence:

• После прогулки у неё немного болела щиколотка.

This is natural and neutral.

You could also hear:

• После прогулки у неё щиколотка немного болела.
• У неё после прогулки немного болела щиколотка.

These all mean roughly the same thing, but the emphasis shifts slightly.

In general:

• earlier position often gives background or setup
• later position can highlight the word more

The version you were given is a very normal way to say it.

Yes, that is grammatically possible, but it is often less idiomatic in this kind of context.

Russian frequently uses у + genitive when talking about:

• body parts
• physical sensations
• injuries
• things someone has

So:

• У неё немного болела щиколотка = more natural in many everyday situations
• Её щиколотка немного болела = possible, but more explicitly focuses on her ankle as a possessed object

A useful rule of thumb: with body parts and pain, у неё... is very common and natural.

Very often, yes.

A common Russian pattern is:

• У меня болит голова. = My head hurts.
• У него болит спина. = His back hurts.
• У неё болела щиколотка. = Her ankle hurt.

The thing that hurts is the subject:

• голова болит
• спина болит
• щиколотка болела

And the person experiencing the pain is expressed with у + genitive:

• у меня
• у него
• у неё

This is one of the most useful patterns to learn for talking about pain and discomfort.

Щиколотка means ankle and is a normal everyday word.

In this sentence it refers to the body part itself—the ankle area that was hurting.

A learner should know that Russian has a few body-part words that may not match English one-for-one in usage, but щиколотка is a standard word and works well here.

The stress is:

• щико́лотка

That can help with pronunciation.

A helpful stress-marked version is:

После прогу́лки у неё немного́ боле́ла щико́лотка.

Approximate pronunciation:

• После = POS-lye
• прогулки = pra-GOOL-kee
• у неё = oo nee-YO
• немного = nee-mna-GO
• болела = ba-LEE-la
• щиколотка = shchee-KO-lat-ka

You do not need a perfect English-style approximation, but the key thing is to notice the stressed syllables.