How can urinary incontinence and the difficulty of performing ablution at university (due to unclean restrooms and the difficulty of removing the hijab) affect the performance of the Dhuhr, Asr, and Maghrib prayers combined?

According to the Hanbalis, a woman suffering from incontinence is permitted to combine two prayers. She is also allowed to resort to dry ablution (tayammum) if her performing ablution (wudu') would necessitate uncovering her 'awrah (private parts). Otherwise, she is not permitted to perform tayammum, nor is she allowed to delay the prayer beyond its prescribed time.