Translation:Will she have received it on Thursday?
People often ask about by so I want to add this: if you want to say by unambiguously in Swedish, that would be till(s) på torsdag or innan torsdag 'before Thursday'. There's also senast på torsdag literally "on Thursday as the latest". In practice you also often hear people say things like … så att hon har den på torsdag 'so that she has it on Thursday'.
They're equally fine but mean something a bit different. "On" refers to Thursday specifically, i.e., we are talking about Friday looking back on Thursday, while "by" refers to the period leading up to (perhaps including) Thursday: we are talking about the state of affairs on Thursday, will she have received it by then?
Yes, I am aware of the differences. Using "on" can mean both of your examples, since the sentence can either refer to whether she'll be in possession of the item at a given point in time, or whether she'll perform the act of receiving it at a given point in time. And as you say, using "by" can only mean the former. It's the same thing in Swedish: på can mean either "on" or "by", and you can use till på if you need to be explicit about the "by" sense. Without context, they're equally fine translations.
I think most people in both languages would skip the weird tense and just go with "will she receive it on Thursday?" if they are wondering about receiving it at a given point in time.
Some kind of Duo hiccups. If you have some other error in the sentence, the machinery doesn't always do a good job at pointing out what it is that it doesn't like in your answer. It just tries to match what you input to the closest accepted answer – and the result isn't always what a human would choose.
Or it could just have been a glitch altogether, that happens too.
Is future perfect used more commonly in Swedish than in English?
I ask because almost all the examples translated into English sound Very stilted and sometimes downright awkward. The meaning of this sentence would most typically be said as "Will she get it on Thursday?" or "Will she have it on (by) Thursday?" I know there are subtle differences, but too subtle for most people to care.
If it is more commonly used, I will do my best to learn this kind of phrase and use it accordingly.
This is hard to answer, but I'm reasonably sure that it varies extensively with different native English speakers. All of these comment threads are full with English speakers who are wildly confused by the structure - but there are frequently those who claim that it's completely natural as well. To make matters worse, some of the sentences teaching this construction are more suitable than others, so some phrases may raise eyebrows even though the construction in itself wouldn't.
All that said, it's not like it's a super-common construction. But it does feature.