Я одолжила зарядку у подруги, а она дала мне ещё и маленький пауэрбанк.

Because the speaker is female.

In Russian, the past tense in the singular shows gender:

• одолжил = a man borrowed / lent
• одолжила = a woman borrowed / lent
• одолжило = it borrowed / lent (neuter)
• одолжили = they borrowed / lent

So Я одолжила... tells you the speaker is a woman.

Here it means borrowed.

That is a very common learner question, because одолжить can mean either to borrow or to lend, depending on the structure:

• одолжить что-то у кого-то = to borrow something from someone
• одолжить кому-то что-то = to lend something to someone

So in your sentence:

• Я одолжила зарядку у подруги = I borrowed a charger from my friend

Compare:

• Я одолжила у подруги зарядку = I borrowed a charger from my friend
• Я одолжила подруге зарядку = I lent my friend a charger

The case pattern tells you which meaning is intended.

Because зарядку is in the accusative case.

The noun зарядка is feminine, and feminine nouns ending in -а usually change to -у in the accusative singular:

• зарядка = nominative
• зарядку = accusative

Here зарядку is the direct object of одолжила:

• Я одолжила что? → зарядку

So the sentence is literally structured as I borrowed what? — a charger.

Here зарядка means a charger.

But this word can be broader than the English word charger. Depending on context, зарядка can mean:

• a phone charger
• a charging cable
• charging equipment in general
• even exercise / warm-up exercises in other contexts

In this sentence, because of пауэрбанк and the general situation, зарядка clearly means some kind of phone-charging device.

A more formal or precise word is often зарядное устройство, but in everyday speech people very often just say зарядка.

Подруги is genitive singular, used after у.

In this sentence, у + genitive means from someone / from someone's possession:

• у подруги = from a female friend

So:

• Я одолжила зарядку у подруги = I borrowed a charger from my friend

This is a very common pattern in Russian:

• взять книгу у брата = to take a book from one’s brother
• занять деньги у друга = to borrow money from a friend

So у here does not mean simple location like at. It marks the person you got something from.

Usually, no. Подруга normally just means female friend.

That is important for English speakers because girlfriend in English can mean either:

• a female friend
• a romantic partner

In Russian:

• подруга = female friend
• девушка can mean girlfriend in a romantic sense, depending on context

So у подруги here simply means from a female friend.

Because а often links two clauses with a slight contrast, switch of focus, or addition from another angle.

In this sentence:

• Я одолжила зарядку у подруги, а она дала мне ещё и маленький пауэрбанк.

The idea is something like:

• I borrowed a charger from my friend, and then she, on top of that, gave me a small power bank too.

So а is not always a strong but. Very often it is a softer connector than that, somewhere between and and but, often with a change of subject or perspective.

If you used и, it would sound more like simple chaining of events. А feels more natural here because the focus shifts from I borrowed to she gave.

Russian often allows pronouns to be omitted, but they are added when the speaker wants clarity, contrast, or emphasis.

Here она helps mark the switch of subject:

• first clause: Я одолжила...
• second clause: а она дала...

So она makes the contrast neat and clear:

• I borrowed..., and she gave...

Without она, the sentence could still be understandable in context, but it would sound less balanced.

Because мне is the indirect object, the person who received something.

The verb дать means to give, and Russian uses the dative case for the recipient:

• дать кому? → мне
• дала мне = gave me

So the structure is:

• она дала мне маленький пауэрбанк
• literally: she gave to me a small power bank

This is very common:

• он дал мне книгу = he gave me a book
• я сказала ей правду = I told her the truth

Ещё и means something like:

• also
• as well
• on top of that
• sometimes even and even

In this sentence it adds the idea that the friend did more than expected:

• она дала мне ещё и маленький пауэрбанк
• she also gave me a small power bank
• she even gave me a small power bank as well

So the feeling is not just simple addition. It often suggests an extra unexpected bonus.

Because пауэрбанк is a masculine inanimate noun, and here it is in the accusative singular.

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

• маленький пауэрбанк = nominative
• маленький пауэрбанк = accusative

So after дала:

• дала что? → маленький пауэрбанк

The adjective matches the noun:

• маленький = masculine singular
• пауэрбанк = masculine singular

If it were animate, the accusative form would often look different.

Yes, it is very common in everyday speech.

Пауэрбанк is a borrowed word from English power bank, adapted to Russian pronunciation and spelling. It is widely used and sounds natural in conversation.

A more formal or technical alternative is:

• внешний аккумулятор = external battery / portable battery pack

But in casual speech, пауэрбанк is probably the word you will hear most often.

Yes, aspect is important here.

Both verbs are perfective:

• одолжила from одолжить
• дала from дать

Perfective verbs present the actions as completed, whole events:

• she borrowed the charger
• the friend gave the power bank

That fits the sentence because it tells a sequence of finished actions.

If imperfective forms were used, the meaning would change and sound less natural here. The sentence is about what happened, not about an ongoing process or repeated habit.

Yes. Russian word order is flexible, but changing it changes the emphasis.

The neutral order here is very natural:

• Я одолжила зарядку у подруги, а она дала мне ещё и маленький пауэрбанк.

You could also say:

• Я у подруги одолжила зарядку...
• ...а ещё и маленький пауэрбанк она дала мне

But those versions shift the focus and may sound more marked, emotional, or contextual.

So the original sentence is a good standard model for everyday speech.