It is recommended to send the weak among women and others ahead from Al-Muzdalifah to Mina at the end of the night, before it gets crowded, but it is recommended for others to stay there until they have prayed Subh in Al-Muzdalifah
وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، حَدَّثَنَا عَمْرٌو، عَنْ عَطَاءٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ كُنْتُ فِيمَنْ قَدَّمَ رَسُولُ اللَّهِ صلى الله عليه وسلم فِي ضَعَفَةِ أَهْلِهِ .
This hadith has been transmitted by Ibn 'Abbas (Allah be pleased with them) with a slight variation of words.