Answer
(Fatwa: 747/703=D/1429)
A Muslim woman can see the body of a Muslim woman except the parts from navel to knee. She can uncover her head, face, chest, shank and arms in front of her Mahram provided there is no fear of lust. She should avoid it if there is fear of lust. But it is not allowed for a woman to open her abdomen and back even before her Mahram.
Note: Why is blouse haram? Who has declared it as so?
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband