она хотела стать медсестрой, (правильно) но сейчас она писательница! но она сейчас писательница! но на данный момент она писательница! но она - писательница! I agree with Lodka: "Прямо сейчас" means "right now", "at this very moment". In this case we use Present Continious in English. But "сейчас" means "now" (continuance, long period). When you put it at the begining of the sentence than you emphasize "сейчас"; or put it after subject if you want to emphasize "писательница".

And by the way, if you say "но сейчас она автор/журналист/космонавт", the "сейчас" would definitely impart to the phrase the meaning that her present occupation is temporary and she'll most probably change it soon or, at least, she hopes to do so. If you'd like to say that writing became her true occupation and she is not going to change it, then it could be: ...но теперь она писательница. OR just (and better) ...но стала писательницей.

Прямо сейчас means "right now", "at this very moment", so it doesn't fit your context. Actually, we don't say автор in Russian if we mean an occupation. When I see the Russian phrase, I'd like to ask, автор of what? In Russian we'd rather say писатель(ница), журналист(ка), автор детских рассказов (not just автор), and so on.

Hello Beneperson. Correct in essentials. However, would be better to rephrase it. "Она хотела стать медсестрой, но сейчас она автор". Sounds more smoothly.

Хотев стать медсестрой, она превратилась в писательницу :))