Am I the only one who initially was going to translate this sentence as "Is Lama an Arab engineer"? I'm new to Arabic, but it seems that عربي and غَريبة are somewhat similar enough for me to confuse them at this point. A big difference is the ghain instead of the ayin, so probably for Arabic speakers there is a big difference.
I'm not sure about Duolingo's intentions (it's a mess) but from an Arab perspective, the word غريب (or the feminine غريبة that is) can be used to mean: 1) stranger or intruder, either a person or an object, or 2) weird in attitude or manners.
so in general i'd say, it is related to something unusual.
so, "foreign" is somewhat in line in meaning somehow. Even though, typically today, we would use the word أجنبي (ajnabiy) for "foreign".
First of all, I have to correct the audio; It's a wrong pronunciation because it is a machine and not recorded by a real person:
Hal Lamá muhandisatun ğaríbah
Secondly, in slow mode, each word would be pronounced on its own and for this reason, the T sound disappears. I will explain this T sound below.
The letter of "Ta-Marbúta" ة is a letter in Arabic that combines H and T. When the word is spelled alone or at the end of the sentence (where the last vowel on the last word in the sentence is not required), the word is simply spelled with (H). However, when the word comes in the middle of the sentence, and usually a vowel on the last letter is needed (for declination), the H changes to (T). For this reason, you hear (Muhandisatan) when you listen to the sentence at full, but (muhandisah) when you click the slow speech button.
To add, the correct way to say (engineer) here, as per the grammar, is (muhandisatun). The (H) changes to (T) as I've explained above, and the vowel here is Tanwin or Nunation (-un). Tanwin in Arabic (at this level for the time being) can be considered as a sign of indefinite article, just like the (a/an) in English and other European languages. When there is no (AL) - i.e. definite article- in the word, then Tanwin takes places. Tanwin and (AL) cannot exist in a single word.
On a side note, most but not all, feminine words in Arabic would end up with Ta-Marbútah. So, it is kind of a feminine marker but it can be tricky sometimes (there are some old masculine names that end in Ta-Marbútah).