All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.
There is no specific punishment for a woman who goes out without wearing the hijaab, travels without a Mahram (permanently unmarriageable man), stays in seclusion with a non-Mahram man, or does other similar matters for which there is no fixed Hadd (corporal punishment determined by Shariah).
Nonetheless, the ruler is entitled to issue Ta'zeer (discretionary punishment) against whoever does that according to his personal discretion, and there is no difference between a woman and a man in this regard.
Ibn Farhoon from the Maaliki School of jurisprudence, said, “...Among which is: what includes disciplining only; such as stealing that which does not necessitate the cutting of the hand, and being in seclusion with a non-Mahram woman…”
Ta'zeer is a punishment that is less than the Hadd and which the ruler decides upon according to his discretion as he deems sufficient for deterrence; but this is a matter that only the ruler is entitled to, not any of the subjects.
Allah knows best.