Pink Belt, you said, "I felt bad, so I left and told someone to help her." That's effective...who did you have help her, one of the guys on the belt who are already harboring ill will towards her?
Did you document her training period during her 30 days? Did you or a training supervisor work with her to show her the correct methods? Or give her some of the tricks to make the job a little easier? Was she given the opportunity to have a graduated work load? Or was she put in the trailers for the entire sort? You need to have a heart to heart with her...present the facts...production numbers, expectations, etc. Document the process.
I was hired on the preload, was the token female and it sucked. Every day was a challenge including dealing with the part-time sups who loved to yell, the guys who thought it would be fun to put all the missorts in my cages to see how I could dig out on my own, or when my load charts would disappear on a regular basis (this was before PAS).
Fast forward 20 years and it seems like some things haven't changed. Please work with her and help her be successful. She might be your boss one day.