Why is she coming to me?

I was recently contacted by my brother's exgf about her being pregnant and him not responding to her calls. Last night at around 3 am she called my mom and then me leaving voicemails about how he neglected her and the unborn child, is not claiming it, wants nothing to do with her and so on and so forth.
The issue is this: we were cool as acquaintances for awhile when she met my brother, but now she is getting on my nerves. She constantly complains About my brother whether it's his unfaithfulness or laziness or anger/violence issues. I have warned her not to get involved with him being that he is the type of person that he is. Her calling me is getting very annoying and I M tempted to say something very tactless but I'm trying to grow as a person. How can I tell her to leave my brother if she knows what's best, and that there is nothing anyone can say to change him? I understand she is hormonal and emotional but her getting knocked up is not my problem. She is neither the first nor the last, I tell her and all his other gfs this, and to no avail.

End contact with her. You've done 'everything' you possibly can, there's no need to take any more action asin telling her to elave your brother. She knows what needs to be done, and what is the correct descions... so let her be the adult.
If you'd like pass the information on to your family that your cutting contact with her so you can 'grow'.

Best of luck,

Gabriella