"She" is perfectly fine here, and "She is selling her last jewel" is accepted as a correct answer. The problem in your proposal is the simple present tense "sells". In English, the simple present is primarily used for habitual actions, actions you perform frequently, repeatedly or on a regular base. Selling your "last" diamond is an action you normally do not repeat. So you have to use the present continous ("is selling") rather than the simple present ("sells").
Thank you very much, that is a great knowledge. But then he can sell something else... Even in this case is it true?
Please, also see this:
Thanks, but this is similar:
I know, that is not a proof. Just an assumption. I also played variously with asterisks...
I am not sure about the complete set of meanings of "gem", the main meaning is a precious stone - drahý kámen, drahokam, and I think that many of the translations "gem" -> "šperk" I see in treq.korpus.cz are actually mistranslations, but still it could be possible.
If "gems" also include whole jewels (made with precious stones or not), it can be used here.
“Gem” generally refers to the stone itself, primarily, but not exclusively, a precious stone. A “jewel” also can be a precious or semiprecious stone. The biggest difference is the additional use of “jewel” to refer to a piece of jewelry, i.e., a decorative item that combines a stone or stones with one or more (usually) precious metals.
So if šperk can be either a single stone or a piece of jewelry, “gem” would be okay, at least in some sentences. But from your last sentence, it sounds like the stone itself would not be called šperk, only the whole item would be. Am I reading that right?
You can't tell the difference without additional information. There is only one verb form for the present tense in Czech and it can have both meanings. Usually it will be clear from the situational context wether a Czech sentence has a meaning corresponding to the simple present or to the continuous present in English. If the context does not provide this kind of information, a Czech speaker can add a temporal adverb such as "teď" to disambiguate a sentence.
The Czech language is not an exception in this respect. Other languages, as for instance German and French, have no direct equivalent to the English present continuous either and use similar means as Czech to differentiate between frequent/habitual and ongoing actions.
Je mange = I eat / I am eating
Je suis en train de manger = I am eating
Ich esse = I eat / I am eating
Ich esse gerade = I am eating (gerade = right now)
For details have a look at The Czech Present Tense and its English Equivalents (Bachelor Thesis, Irena Kajerová, Olomouc 2009)
Yes, in some meanings of the word "final" can definitely be used. "Poslední" can also be something last on the timeline. But in other cases, "závěrečný" might be more appropriate.
His final year = Jeho poslední rok
His final decision = Jeho poslední rozhodnutí
His final exam = Jeho závěrečná zkouška
Jeho poslední zkouška = His last exam
Jeho poslední věc = His last thing
On skončil v závodě poslední. = He finished last in the race.
PS: It's never too late :-)