The Messenger of Allah ﷺ used to pray thirteen rak'ahs during the night, observing the witr prayer with nine (or as she said). He used to pray two rak'ahs while sitting and pray two rak'ahs of the dawn prayer between the adhan and the iqamah. (Using translation from Abū Dāʾūd 1350)
أَنَّ رَسُولَ اللهِ ﷺ كَانَ يُصَلِّي مِنَ اللَّيْلِ ثَلَاثَ عَشْرَةَ رَكْعَةً يُوتِرُ بِتِسْعٍ أَوْ كَمَا قَالَ وَيُصَلِّي رَكْعَتَيْنِ وَهُوَ جَالِسٌ وَرَكْعَتَيِ الْفَجْرِ بَيْنَ الْأَذَانِ وَالْإِقَامَةِ