ANSWER:

She can make wudhu from underneath her abaya. 

If a woman is in a public place where men are all around and there is no cover area or washroom and maby there is a tap in an open area fro example in muzdalfa how can the woman do ablution

Ablution (Wudhu) | April 29, 2018 9:34 am
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I was in the shower and making wudu and then i was using quiet a small amount water and I was washing my face and I thought I could use even less water and turn off the water with my wrists but I didn’t do in the 2nd time I was washing my face but in The third time I did does this mean I wasted water because water was running when I was washing my face?
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Can someone use flowing water that all every body pass trough it even animals always drink it can we use it to purified our self (2) can we use it for ablution. Please back it up by Quran or hadith