Whoever said send flowers is way off. That is so impersonal and almost insulting. Ignore that poster, for the love of God.

Tell her she doesn't deserve the shit she is going thru. Maybe also tell her she is not alone, refer her to some stories on this site? Google Jamie King

Care package idea is really cute OP. Trashy mags (that you check first for baby crap), snacks, maybe some bubble bath or candles, maybe a new sweater or top from her fave store (lululemon or somewhere that you can get something really soft and loungey), and a short and sweet note like what the PPs have suggested.