She has passed on her genetic material at the very least.
Including her breeding problems, most likely:
"Nevertheless, Rachel's dam, Lotta Kim, also had issues with foaling.
"Lotta Kim has only produced two other foals besides Rachel Alexandra, according to Jockey Club reports. An Empire Maker colt born in 2007 was euthanized in 2009 due to wobbler's syndrome and Samantha Nicole, a 2-year-old full sister to Rachel, was purchased by Stonestreet at the Keeneland November sale for $700,000."