Can I make a bracha in front of my sister if she is wearing pants?
Answer:
Yes, this would be permitted.
Although pants are not modest wear for women, they do cover up the covered parts of the body, and and it is therefore permitted to make a berachah in front of a lady wearing pants. The prohibition of reciting berachos in front of immodestly dressed women is on account of the concern for hirhurim (see Mishnah Berurah 75:8), and this would not apply for a girl dressed in pants.
