Sounds like you let her off easy...... get some revenge in.
A well written letter to her superior, giving factual details about why she is bad for the business, with a sign off mentioning that you are happy to discuss in person should s/he wish to follow up.
At the very least, if executed well (I very much doubt this is possible, given your low IQ, poor writing abilities and latent spasticity), it would plant some seeds of doubt, which may grow over time and result in some trouble for her in the future.