Tot i que el pebrot és bo, la meva filla prefereix el cogombre perquè li agrada més.

Yes. Tot i que is a fixed expression meaning although or even though.

It introduces a contrast:

Tot i que el pebrot és bo...
= Although the pepper is good...

It is very common in Catalan and is best learned as one chunk.

Catalan often uses the definite article where English does not, especially with nouns used in a general or class-like sense.

So:

el pebrot és bo
literally the pepper is good, but naturally this can mean pepper is good

and

prefereix el cogombre
can mean she prefers cucumber / the cucumber, depending on context.

This is very normal in Catalan. English drops the article more often than Catalan does.

Because bo is the form normally used after the verb:

el pebrot és bo

But bon is the shortened form usually used before a masculine singular noun:

un bon pebrot

So:

• és bo = correct
• un bon pebrot = correct

This is a very common pattern with bo / bon.

Yes, and the difference is about nuance.

• és bo usually describes a more general quality: good, healthy, beneficial, or a good thing
• està bo often means it tastes good or it is delicious

So this sentence sounds more like:

Even though pepper is good, my daughter prefers cucumber...

If you wanted to emphasize taste specifically, many speakers might naturally say està bo instead.

In Catalan, possessives are often used together with the definite article:

• la meva filla
• el meu pare
• la nostra casa

English usually says my daughter, without the, but Catalan normally includes the article.

So la meva filla is the standard way to say my daughter.

Prefereix is the third person singular present tense of preferir.

Here it means:

la meva filla prefereix
= my daughter prefers

It is singular because the subject, la meva filla, is singular.

This verb often shows -eix- in the present tense:

• prefereixo
• prefereixes
• prefereix
• preferim
• preferiu
• prefereixen

Here perquè means because.

So:

... perquè li agrada més
= ... because she likes it more

This is different from per què as two words, which usually means why or for what:

• Per què ho fa? = Why does she do it?

A useful shortcut:

• perquè = because
• per què = why / for what

Agradar works differently from English to like.

Catalan structures it more like to be pleasing to.

So:

li agrada el cogombre

literally means something like:

the cucumber is pleasing to her

That is why you get:

• li = to her
• agrada = is pleasing
• el cogombre = the thing being liked

So li agrada més means she likes it more, but the Catalan grammar is built differently from English.

Li refers to la meva filla.

So in this sentence:

la meva filla prefereix el cogombre perquè li agrada més

the li means to her = to my daughter.

Catalan often repeats this kind of reference with a pronoun even when the person has already been mentioned.

Because the grammatical subject of agradar here is el cogombre, which is singular.

Think of it this way:

• El cogombre li agrada = The cucumber pleases her
• Els cogombres li agraden = Cucumbers please her

So:

• singular noun → agrada
• plural noun → agraden

It agrees with the thing liked, not with the person who likes it.

Més means more.

In this sentence, the comparison is understood from the context. She likes the cucumber more than the pepper mentioned earlier.

So:

li agrada més
= she likes it more

Catalan, like English, can leave the second part of the comparison unstated when it is already clear.

It is a little repetitive, but it is still natural.

• prefereix el cogombre states the preference
• perquè li agrada més explains the reason for that preference

So the sentence is doing two things:

1. saying what her choice is
2. explaining why

English can do the same:

My daughter prefers cucumber because she likes it more.

So it is not wrong or strange; it just makes the logic explicit.