Look, I think this still insists on a fake dilemma.
One of the most natural thing to ask someone like Lina is about their earliest educational experiences, etc. It would automatically and organically come up that she was born in Afghanistan and moved to Germany at age whatever. It is also a totally on-topic question to probe the fact that she achieved what she did in a language that is not her native language. There is nothing intrusive or harassing about those questions in that context. On the contrary, especially in light of what is being reported about it obviously takes active effort and wilful blindness to make her background invisible.
Being interviewed as an over-archiever, or the person who saved a passerby's life, etc. is a totally different situation from being pestered by randoms looking to establish that you are not "really" German. If you're interviewing a random person on a random topic unrelated to migration, say a Professor who just won a grant, of course you shouldn't go in with “So where are you 'really' from?" a propos of nothing. But if you're asking salient questions that bring it up, or if their migration history is known (e.g., because of where they obtained their first degree) and you have a topical question related to that, of course you can ask. And then respect whether they want to talk about it or not. People don't owe you an answer to the question where they are from to satisfy your curiosity, but you do owe it to them not to make it invisible if they decide it's relevant.
There is no real-life dilemma here or need to look for complications that aren't there.
There's only a simple rule: don't be racist and don't pander to racists.
