Oh Lindsey...... that is just awful, what a horrible person she is, I think you just need to distance yourself from them (i know you have already), in your head too. Some times you just cant win with family, no matter what you do, and so the only way is to keep your distance. It is a shame for your brother, he has to make up his own mind, which he has done by look of it.
Now if i was in your shoes..... part of me would be so mad, i would have to have my say, probably in a letter, one each to her and your brother, i would write it all down how i feel hurt, and tell her to please stop bad mouthing you to people, she can think what she wants, but she is not to bad mouth you.
Just pour it all out, and to your brother tell him, you understand he will stand by her, but explain your point of view, and how if makes you feel, he should know Lindsey............. and end it by telling him you will always be his sister, and will be there if he needs you.
Now the level headed part, would advise do nothing, and hope it will all blow over, i personally would do the letters, even if no resolution you deserve your say, why should she get away with it......... keep copies of your letters too.
Good luck, and dont forget once you decide what to do, if anything..... its upto them, you know in your heart, you did nothing to deserve this, everyone that knows you, will also see that too - just let them get on with it, and you ignore her too.
Oh and a big congratulations to you both, i didnt know about the baby
