La figlia va in biblioteca ogni mercoledì pomeriggio.

La is the feminine singular definite article, meaning the.

So:

• la figlia = the daughter

It matches figlia because figlia is a feminine singular noun.

In Italian, articles are used more regularly than in English, so where English says daughter in some contexts, Italian often needs la figlia if it means the daughter.

Va is the third person singular present tense of andare, which means to go.

The present-tense forms of andare are:

• io vado = I go
• tu vai = you go
• lui/lei va = he/she goes
• noi andiamo = we go
• voi andate = you all go
• loro vanno = they go

So la figlia va means the daughter goes.

Italian uses the present tense for habitual or repeated actions, just like English does in sentences such as She goes to the library every Wednesday afternoon.

So va does not mean only is going right now. In this sentence it expresses a routine:

• La figlia va in biblioteca ogni mercoledì pomeriggio
  = she goes there regularly, every Wednesday afternoon

With places like biblioteca, Italian often uses andare in + place to mean going to that type of place, especially in a general or functional sense.

So:

• andare in biblioteca = to go to the library

This is very natural Italian.

Alla biblioteca can exist, but it often sounds more like going to the library building/location specifically. In many everyday cases, in biblioteca is the more idiomatic choice.

In expressions like in biblioteca, Italian often omits the article after certain prepositions when referring to common destinations in a general way.

So:

• in biblioteca
• in chiesa
• in banca

This is something you often learn as a fixed pattern.

If you add an article, the meaning can become more specific, as in nella biblioteca della scuola = in the school library.

Ogni means every.

So:

• ogni mercoledì = every Wednesday

A useful grammar point is that ogni is followed by a singular noun:

• ogni giorno = every day
• ogni settimana = every week
• ogni mercoledì = every Wednesday

English learners sometimes expect a plural idea because the meaning is repeated, but Italian uses the singular after ogni.

Yes. Ogni mercoledì and tutti i mercoledì can both mean every Wednesday.

Compare:

• ogni mercoledì = every Wednesday
• tutti i mercoledì = every Wednesday / all Wednesdays

The first uses ogni + singular noun.
The second uses tutti i + plural noun.

Both are correct, but ogni mercoledì pomeriggio is very natural in this sentence.

Mercoledì has a written accent because the stress falls on the final syllable.

Days like this are typically invariable, which means the form does not change between singular and plural.

So:

• mercoledì = Wednesday
• i mercoledì = Wednesdays

The word stays mercoledì.

Pomeriggio means afternoon.

In this sentence, ogni mercoledì pomeriggio works as a time expression meaning:

• every Wednesday afternoon

Italian often places time expressions after the verb phrase, just as here:

• va in biblioteca ogni mercoledì pomeriggio

That word order is completely natural.

Yes, Italian word order is somewhat flexible, although the given version is very natural.

For example, you could also say:

• Ogni mercoledì pomeriggio, la figlia va in biblioteca.

This puts the time expression first for emphasis or style.

The original sentence is the most neutral and straightforward order:

• subject + verb + place + time

Yes, Italian often drops the subject pronoun, and sometimes even the noun subject if it is already clear from context.

So if everyone already knows who you are talking about, you might hear:

• Va in biblioteca ogni mercoledì pomeriggio.

Because va already tells you the subject is he/she/it.

However, in your sentence la figlia is included to make the subject explicit.

Usually, yes: figlia means daughter.

It is the feminine form related to:

• figlio = son
• figlia = daughter

In some contexts, especially older or literary ones, words from this family can have broader meanings related to child or offspring, but in normal modern usage figlia is understood as daughter.