اختي في المستشفى دلوقتي مع الدكتورة.

اختي means my sister.

It is made from:

• أخت / اخت = sister
• -ي = my

So the -ي is a possessive ending attached directly to the noun.

In Egyptian Arabic, learners often hear it pronounced something like okhti.

The more careful spelling is أختي with a hamza on أ.

In informal writing, especially in texting or casual online writing, many people leave the hamza off and write اختي. This is very common and usually does not cause confusion.

So:

• أختي = more standard spelling
• اختي = very common casual spelling

In Arabic, present-tense sentences like this usually do not use a separate word for is/am/are.

So اختي في المستشفى literally looks like:

• my sister
• in/at the hospital

But it means:

• My sister is in/at the hospital

This is a normal feature of Arabic, not something missing by accident.

If you wanted the past, you would usually add a verb, for example with كان.

It can match either in the hospital or at the hospital in English, depending on context.

• في literally means in
• المستشفى means the hospital

But English often says at the hospital where Arabic still uses في.

So in this sentence, both of these can fit the situation:

• in the hospital
• at the hospital

A natural Egyptian-style pronunciation would be something like:

okhti fil-mostashfa dilwa'ti maʿ ed-doktora

A few notes:

• اختي → okhti
• في المستشفى often sounds like fil-mostashfa
• دلوقتي is often pronounced dilwa'ti or delwa'ti
• مع contains the Arabic sound ع, often written ʿ
• الدكتورة is pronounced ed-doktora, not el-doktora

Two sounds that English speakers often find hard:

• خ in اختي: a rough sound like ch in Scottish loch or German Bach
• ع in مع: a deep throat sound with no exact English equivalent

دلوقتي means now or right now.

In Egyptian Arabic, ق is very often pronounced as a glottal stop rather than a strong q sound. That is why دلوقتي is commonly pronounced dilwa'ti / delwa'ti.

So:

• spelling: دلوقتي
• common Egyptian pronunciation: dilwa'ti

This word is strongly associated with spoken Egyptian Arabic.

Yes, عند الدكتورة could also work, but the nuance is a little different.

• مع الدكتورة = with the doctor
• عند الدكتورة = at the doctor's / with the doctor in the sense of being at her place or in her care

In your sentence, مع الدكتورة emphasizes that your sister is with the doctor right now.

If the idea is more specifically that she is at the doctor’s appointment, many speakers might also say عند الدكتورة.

So both can be natural, but:

• مع focuses on being together with someone
• عند often focuses on being at someone’s place or under their attention/care

Yes. الدكتورة refers to a female doctor.

Compare:

• الدكتور = the male doctor
• الدكتورة = the female doctor

Also, because it has ال, it means the doctor, not a doctor.

So:

• مع الدكتورة = with the female doctor
• مع دكتورة = with a female doctor

This happens because د is a sun letter.

In Arabic, when ال comes before a sun letter, the l sound of ال is not pronounced separately. Instead, the next consonant is doubled.

So:

• written: الدكتورة
• pronounced in Egyptian: ed-doktora

Compare that with words starting with a moon letter, where the l is clearly pronounced.

This is a pronunciation rule; the spelling stays the same.

The order can change. Arabic is more flexible than English with this kind of sentence.

Your sentence is:

اختي في المستشفى دلوقتي مع الدكتورة

That is fine and natural. But you could also hear:

• اختي دلوقتي في المستشفى مع الدكتورة
• دلوقتي اختي في المستشفى مع الدكتورة

The meaning stays basically the same, but the emphasis changes:

• putting دلوقتي earlier emphasizes right now
• putting في المستشفى earlier emphasizes the location

So the original order is not the only possible one.

It is mainly Egyptian Arabic, especially because of دلوقتي.

That word is colloquial Egyptian. In Modern Standard Arabic, you would more likely say:

• أختي في المستشفى الآن مع الدكتورة
• or more formally أختي في المستشفى الآن مع الطبيبة

So:

• دلوقتي = clearly Egyptian colloquial
• the rest of the sentence is close enough that most Arabic speakers would still understand it easily

Because in fast speech, في plus الـ often runs together smoothly.

So:

• في + المستشفى
• becomes something like fil-mostashfa

This is not a different word or different grammar. It is just natural connected pronunciation.

You will often hear this kind of merging in spoken Arabic.