Ablam bu sabah erkenden işe gitti.

Abla means older sister.
Ablam means my older sister.

The -m at the end is a possessive ending meaning my. So:

• abla = older sister
• ablam = my older sister

This is very common in Turkish: instead of using a separate word for my, Turkish often adds a possessive suffix directly to the noun.

Turkish often leaves out benim (my) because the possessive meaning is already clear from the suffix.

So both of these are possible:

• ablam = my older sister
• benim ablam = my older sister

But ablam is usually enough in normal speech.
Using benim can add emphasis, like my older sister specifically.

It specifically means older sister.

If you want to say younger sister, Turkish uses kız kardeş.
So abla is not a general word for sister in all situations; it refers to an older one.

Also, Turkish speakers sometimes use abla for a slightly older woman in a friendly or respectful way, not only for a biological sister.

Bu sabah means this morning.

• bu = this
• sabah = morning

Together, they function as a time expression. Turkish commonly puts time expressions near the beginning of the sentence.

So in this sentence:

• Ablam = my older sister
• bu sabah = this morning
• erkenden = early / very early
• işe gitti = went to work

Erken means early.

Erkenden is an adverb meaning something like:

• early
• quite early
• nice and early
• earlier than usual, depending on context

It often sounds a bit more natural and expressive than plain erken in some sentences.

Compare:

• erken gitti = went early
• erkenden gitti = went early / went nice and early

In this sentence, erkenden gives the sense that she left fairly early in the morning.

Because the verb gitmek (to go) usually takes the dative case, which often means to / toward.

So:

• iş = work
• işe = to work

That is why işe gitmek means to go to work.

The other forms would mean different things:

• işi = the work / his-her-its work / work as an object, depending on context
• işte = at work / in the work

With gitmek, you normally use the destination in the dative:

• okula gitti = he/she went to school
• eve gitti = he/she went home
• işe gitti = he/she went to work

Gitti comes from the verb gitmek (to go).

Its parts are:

• git- = verb stem
• -ti / -dı / -du / -dü = definite past tense ending, chosen by vowel harmony and consonant changes
• here it becomes gitti = he/she/it went

So:

• gitmek = to go
• gitti = he/she went

Some other past forms are:

• gittim = I went
• gittin = you went
• gittik = we went
• gittiler = they went

In your sentence, gitti matches the third person singular subject ablam.

Turkish normally uses Subject + Time/Other information + Object/Complement + Verb.

So this sentence follows a very typical Turkish pattern:

• Ablam = subject
• bu sabah erkenden = time/manner information
• işe = destination
• gitti = verb

Putting the verb at the end is one of the most basic sentence patterns in Turkish.

Yes, Turkish word order is flexible, but changing it usually changes the focus or emphasis.

The neutral version is:

• Ablam bu sabah erkenden işe gitti.

Other possible orders include:

• Bu sabah ablam erkenden işe gitti.
  Emphasizes this morning a little more.

• Ablam işe bu sabah erkenden gitti.
  Still understandable, but less neutral.

• İşe ablam bu sabah erkenden gitti.
  Stronger focus on to work.

For learners, the original order is the safest and most natural to start with.

Yes.

If you remove bu sabah, you get:

• Ablam erkenden işe gitti.
  = My older sister went to work early.

If you remove erkenden, you get:

• Ablam bu sabah işe gitti.
  = My older sister went to work this morning.

If you remove both:

• Ablam işe gitti.
  = My older sister went to work.

So bu sabah gives the time, and erkenden adds the idea of early.

It can suggest both, depending on context.

Most often, işe gitmek is the normal expression for to go to work in the everyday sense of going for your job.

But literally it is to go to work / to the job / to the workplace. In many real situations, those ideas overlap.

So in this sentence, English would naturally say went to work, not something more literal like went to the work.

Yes, it is completely natural.

It sounds like ordinary, everyday Turkish.
The combination bu sabah erkenden işe gitti is especially natural for describing someone leaving for work earlier in the morning.

A native speaker would understand it immediately and find it normal.