Дочке было обидно, что подруга ушла и ничего не сказала.

Because Russian often uses the dative case for the person who experiences a feeling or state.

So Дочке было обидно literally means something like:

To the daughter, it was hurtful / upsetting.

This is a very common Russian pattern:

• Мне грустно = I am sad
• Ему холодно = He is cold
• Нам было весело = We were having fun
• Дочке было обидно = The daughter felt hurt / upset

So дочке is not the subject in the English sense. It is the experiencer of the emotion.

Because было does not agree with дочке here.

In this sentence, было обидно is an impersonal construction. The key idea is:

It was hurtful/upsetting to the daughter.

In Russian, with predicative words like обидно, грустно, жалко, трудно, легко, the past tense of быть is usually the neuter singular form:

• было грустно
• было жалко
• было трудно
• было обидно

So было is used because the construction is impersonal, not because of the gender of дочка.

Обидно is a predicative word meaning something like:

• hurtful
• offensive
• upsetting
• it hurt someone’s feelings

In this sentence, it does not mean simple sadness. It suggests that the daughter felt emotionally hurt, slighted, or offended by what happened.

Compare:

• Мне грустно = I feel sad
• Мне обидно = I feel hurt / offended / upset

So обидно often carries the idea that someone's feelings were hurt by another person’s action.

Because что introduces a subordinate clause.

The sentence is:

Дочке было обидно, что подруга ушла и ничего не сказала.

The first part is the main clause:

Дочке было обидно = The daughter felt hurt

The second part explains what she felt hurt about:

что подруга ушла и ничего не сказала = that her friend left and said nothing

In Russian, subordinate clauses introduced by что are normally separated by a comma.

Because the subject is подруга, which is feminine.

Russian past tense verbs agree in gender and number with the subject:

• masculine: ушёл, сказал
• feminine: ушла, сказала
• neuter: ушло, сказало
• plural: ушли, сказали

Since подруга means female friend, you get:

• подруга ушла
• подруга сказала

And in the sentence:

подруга ушла и ничего не сказала

both verbs refer to подруга, so both are feminine singular.

They are perfective because the sentence refers to completed actions:

• ушла = left / went away
• не сказала = did not say

The speaker is talking about specific finished events: the friend left and didn’t say anything.

If you used imperfective forms, the meaning would change. For example, imperfective often suggests process, repetition, or background action, not a single completed event.

Here, perfective is natural because the daughter was upset by a concrete result: the friend left and said nothing.

Because Russian normally uses negative concord, often called “double negation” in English explanations.

So when the verb is negative, words like nothing, nobody, nowhere are also negative:

• Я ничего не знаю = I know nothing
• Он никого не видел = He saw nobody
• Мы никуда не пошли = We went nowhere

So:

ничего не сказала
literally: didn’t say nothing, but in correct English: didn’t say anything / said nothing

This is standard Russian grammar, not an error.

Russian often leaves out something that is clear from context.

In this sentence, it is understood that the friend did not say anything to the daughter before leaving. Russian does not need to state that explicitly if it is obvious.

If you wanted to make it explicit, you could say:

• ничего ей не сказала = didn’t say anything to her
• ничего не сказала дочке = didn’t say anything to the daughter

But the shorter version sounds perfectly natural because the context already makes the relationship clear.

Yes.

For example:

Ей было обидно, что подруга ушла и ничего не сказала.

This means the same thing: She felt hurt that her friend left without saying anything.

The difference is mainly one of style and clarity:

• дочке names the person directly
• ей uses a pronoun

If the daughter has already been mentioned, ей is often very natural. If you want to identify her clearly, дочке is better.

They are related, but not the same.

Дочке было обидно focuses on the feeling/state:

• the daughter felt hurt
• the situation was upsetting to her

Дочка обиделась uses the verb обидеться:

• the daughter got offended
• the daughter took offense
• the daughter became upset/hurt

So:

• Мне было обидно = I felt hurt
• Я обиделся / обиделась = I got offended / I took offense

In your sentence, было обидно sounds a bit softer and more descriptive of her emotional state.

Yes, Russian word order is flexible, though not completely free.

The neutral order here is:

Дочке было обидно, что подруга ушла и ничего не сказала.

You could also say:

Что подруга ушла и ничего не сказала, дочке было обидно.

That version is more marked and gives extra emphasis to the reason for her hurt feelings.

Russian word order often changes to highlight:

• what is already known
• what is new information
• what is being emphasized

So the original sentence is the most natural, neutral version for most contexts.