Can you say "When can she show up?"
yes, that would be a more natural way to say it. Or, "When can she come?"
It is accepted now.
"When she can appear?" is ungrammatical in English. No native speaker would phrase this question like this. The correct form is "When can she appear?"
The noun and verb usually are not reversed in a question in Portuguese. One simply needs to do the reversal when they translate it into English.
"when can she turn up" should be accepted
"when is she able to appear?" is wrong.
I guess only her publicity agent would ask this?
"When can she get here?" would be colloquial English. "When can she appear" sounds more like a visit to court ("when can she appear before the magistrates?")
Is the common way of saying when can she come? In english "appear" is usually reserved for "appearing in or at court"
I was thinking of appearing as a ghost ;) But "aparecer" is a handy way of expressing in Portuguese someone showing up; just not in English.
Or on stage
Why not ‘when can she come’?