Is it permissible for my friend to obey her family by giving two drops of her blood to her aunt-in-law for her to wash with – in order to break a spell of imprisonment on her, according to their beliefs – even though she is convinced that what she is doing is haram, just to escape their pressures?

It is not permissible to obey parents in washing with impure blood, ascribing influence to other than Allah, and because it involves spreading innovations and superstitions. If they think that the evil eye originated from you, then the Sunnah is for the one who cast the evil eye to wash his face, hands, elbows, knees, and the ends of his feet, and then the afflicted person should wash himself with that water.