Подруга стояла у двери такая смущённая, что я сразу приняла её извинение.

Yes. Russian usually makes this distinction explicitly:

• друг = a male friend
• подруга = a female friend

So подруга tells you right away that the friend is female. Depending on context, подруга can sometimes also mean girlfriend, but in many ordinary sentences it simply means female friend.

Стояла literally means was standing. Russian often prefers a concrete verb of position or movement where English might just say was.

So instead of something like The friend was by the door, Russian says The friend was standing by the door. This creates a more vivid image and sounds natural.

Also, стоять suggests not just location, but posture and the scene at that moment.

Because у requires the genitive case.

• дверь = nominative
• двери = genitive singular

So:

• у двери = by the door / at the door

This is a very common pattern in Russian:

• у дома = by the house
• у окна = by the window
• у стола = by the table

Here it means by the door or at the door.

Russian у often means near / by / next to. It does not necessarily mean the person is touching the door or standing directly in the doorway, just that she is positioned there.

This is a very common Russian pattern meaning so ... that.

• такая смущённая, что... = so embarrassed that...

The structure is:

• такой / такая / такое / такие + adjective, что ...
• literally: such a ... that ...
• naturally in English: so ... that ...

Examples:

• Он был такой уставший, что сразу уснул. = He was so tired that he fell asleep immediately.
• Она была такая счастливая, что плакала. = She was so happy that she cried.

Because they agree with подруга, which is feminine singular.

So:

• подруга = feminine singular
• такая = feminine singular
• смущённая = feminine singular

Russian adjectives and adjective-like words must agree with the noun they describe in gender, number, and case.

The long form is the normal choice here because it describes what she looked like in the situation:

• смущённая = embarrassed

The short form adjective is less natural here. Short forms are often used more for stating a condition in a more formal or compact way, while the long form is common in everyday descriptive speech.

So Подруга стояла ... смущённая sounds natural and descriptive: we are being shown her appearance.

Historically, it comes from a participial form, but in sentences like this learners can usually treat it as an adjective meaning embarrassed.

That is often the most useful approach at this level:

• смущённый / смущённая = embarrassed

You do not need to analyze it deeply to understand this sentence.

Russian word order is flexible, and this placement sounds natural because it builds the scene step by step:

• Подруга стояла — the friend was standing
• у двери — by the door
• такая смущённая — so embarrassed
• что... — that...

This order lets the speaker first set the scene, then focus on her emotional state, then give the result.

English often has stricter word order, but Russian can move parts around for rhythm or emphasis.

Yes, принять literally can mean to take or to receive, but it also very often means to accept.

Here:

• приняла её извинение = accepted her apology

This is a standard use of принять:

• принять решение = make/accept a decision
• принять помощь = accept help
• принять извинение = accept an apology

So this is a normal collocation.

Russian often uses the singular извинение where English might use either apology or apologies.

Here:

• её извинение = her apology

It refers to one act of apologizing. Russian singular sounds completely natural.

Here её means her in the possessive sense:

• её извинение = her apology

This её does not change form here; it is the normal possessive pronoun. English speakers often expect more visible case changes, but её stays the same in many contexts.

So it is best understood simply as:

• её книга = her book
• её извинение = her apology

This is a very typical Russian contrast.

• стояла is imperfective because it describes the background situation or ongoing scene: she was standing
• приняла is perfective because it describes a single completed action: I accepted

So the sentence works like this:

1. background: she was standing there, looking embarrassed
2. result: I immediately accepted her apology

This is one of the most common uses of aspect in narration.

Сразу means immediately / right away.

So:

• я сразу приняла её извинение = I immediately accepted her apology

It shows that the speaker reacted at once, because the friend looked so embarrassed.

Yes, very clearly.

The pattern такая ... что ... sets up a consequence:

• she looked so embarrassed
• that I immediately accepted her apology

So the idea is not just description. Her visible embarrassment influenced the speaker’s decision.

Yes, that is close to the Russian structure. A more natural English rendering would usually be something like:

• My friend was standing by the door, so embarrassed that I immediately accepted her apology.

Or:

• My friend stood by the door looking so embarrassed that I immediately accepted her apology.

The second version often captures the Russian feeling especially well, because смущённая describes how she looked.