Divorce Support Forums: Can somebody help me? Advice on divorce in PA?

Hi everyone,
I'm writing this note on behalf of my mother who is in a very difficult situation. After my mother has put her heart, body and soul into raising my sister and I, she has finally come to the conclusion that putting up with my father's abuse is no longer worth it. All of us have been encouraging her to pursue the route of divorce, which we know has been in her heart all along. The issue is a complicated one but the real hindrance is the issue of finances and how they will get split up.
My mother has literally managed EVERY single aspect of our family life since she was married - she was physically, mentally, emotionally responsible for everything. She worked a stressful full time job, raised two daughters, managed the daily activities of the house and ALL aspects of family/life management. My father was only incharge of working his full time job - when he came home at night, he had no responsibilities. My mother has suffered from all sorts of health complications as a result of being so overworked and has additionally suffered so much emotional abuse and negligence from my father who truly at the end of the day, only cares about himself, his health, his wellbeing, and his professional development.
I recently got married and my husband and I returned home for a few weeks to be with my family. Seeing his behavior up close after being away for a few years, brought back so many horrible memories and made me realize just how awful my mother's life has become because of him.
The reason why I write hee is because I am really unsure about the divorce laws in PA and how their assets will be split up. I have heard that everything is split 50/50 - but what about when both parties didn't work 50/50 to build a life together? What if in reality one member was putting in 95% of the work??? How does the court view this? My father is in tip-top health, has a great profession, lives in a beautiful house all because of the effort, nurturing, energy and soul that my mom put into our lives. Without her nothing would be possible - the only thing my dad did was work a job. Now what? Any advice on what to do so that my mom isn't totally screwed over and that she is left in a situation where she isn't totally at loss?
Additionally, when a couple is going through divorce, can one member get a restraining order of some sort against the other to prevent harrassment, etc?
Thanks