Mi amiga dice que en marzo siempre encuentra más energía para estudiar que en febrero.

Because mi without an accent is the possessive adjective meaning my.

• mi amiga = my friend
• mí with an accent is a pronoun meaning me, usually after a preposition: para mí, sin mí

Also, mi does not change for gender, so it works with both:

• mi amigo
• mi amiga

Spanish often leaves out subject pronouns when they are not needed.

Here, the subject is already clear from Mi amiga, so adding ella would usually sound unnecessary. Spanish prefers:

• Mi amiga dice...

rather than:

• Mi amiga ella dice...

You would only add ella for emphasis, contrast, or clarification.

No. It has two different jobs here.

1. In dice que, que means that

   • Mi amiga dice que... = My friend says that...

2. In más energía ... que en febrero, que means than

   • más ... que = more ... than

So the same word appears twice, but with two different meanings.

Because Spanish normally uses en with months to mean in:

• en marzo = in March
• en febrero = in February

This is the standard way to talk about something happening during a month.

In Spanish, months usually appear without an article when you are simply saying in March, in February, etc.

So you normally say:

• en marzo
• en febrero

Using an article with months is possible in some other structures, but not in this basic time expression.

Because the sentence describes something habitual or generally true, not a one-time event.

• dice = she says
• encuentra = she finds

The word siempre strongly suggests a repeated pattern, so the present tense is natural:

• siempre encuentra = she always finds

This is the Spanish present used for regular habits, just like in English.

After a verb like decir when you are reporting something as a fact or statement, Spanish normally uses the indicative, not the subjunctive.

So:

• Mi amiga dice que... encuentra...

is normal because she is stating something she considers true.

You would expect the subjunctive more often after expressions of doubt, emotion, denial, or uncertainty.

It comes from the verb encontrar.

Here it is:

• 3rd person singular
• present tense
• matching mi amiga

So:

• yo encuentro
• tú encuentras
• él/ella encuentra

This verb is also a stem-changing verb in the present tense:

• o → ue

So encontrar becomes encuentra, encuentras, encuentro, etc.

Because this is a comparison of quantity/amount, not quality.

• más energía = more energy

Use más with nouns when you want to say more:

• más tiempo
• más dinero
• más energía

Mejor means better, so it would refer to quality, not amount.

Because para + infinitive is the normal way to express purpose when the subject stays the same.

• energía para estudiar = energy to study / for studying

The idea is that my friend is the one who studies, so Spanish uses the infinitive:

• para estudiar

If the subject changed, Spanish would usually use para que + subjunctive instead.

Because that is a very natural position for adverbs like siempre in Spanish.

• siempre encuentra = very common and natural

Spanish word order is more flexible than English, so you may also hear other placements in some contexts, but here siempre encuentra sounds smooth and standard.

Because Spanish often leaves out repeated words when the meaning is already clear.

The full idea is something like:

• in March she finds more energy to study than she does in February

Spanish does not need to repeat the whole verb phrase again. So:

• más energía para estudiar que en febrero

is a natural, compact comparison.