Bismillah

Al-jawab billahi at-taufeeq (the answer with Allah's guidance)



To do Ruku' (bow) is Fardh.

Allah Ta'ala says,

"Establish your prayers, pay the obligatory charity, and bow with those who bow." (2:43)


Ruku' of a woman:


"A woman should bend slightly in Ruku; without spreading her fingers out completely. However, she must contract herself and place her palms on her knees and bend them slightly . She must not spread out her arms as this is more concealing for her. " (Raddul Muhtar, Bahrur Raiq)


It is stated in the Fataawaa Aalamgiriyyah:

"As for a female she must bend slightly in Ruku' without spreading her fingers out. She must keep them together on her knees by merely placing the palms. She must bend her knees slightly and not spread her arms out.

Please refer to this: http://www.muftisays.com/qa.php?viewpage=viewQA&question=3751



And Only Allah Ta'ala Knows Best.