I have friend who has never been baptized. She originally came from Catholic parents who later divorced and for some reason she was never baptized. She believes in Jesus Christ, that she is a child of God, but does not necessarily want to embrace the Catholic faith.  She wants to be baptized a Christian but does not necessarily want to join a church. She is an adult, age 40, and as a practicing Catholic I do not know what to advise her to do.  Can I baptize her myself?

You could baptize her yourself if she is in danger of death, but absent that urgency, you should encourage her to be baptized in the Catholic Church.  If she believes in Jesus Christ and wants to be baptized, she is actually hungering for a connection with the one true Church which he founded. 
 
You should continue to work with her and answer her questions as they arise.  You should also encourage her to listen to my show, “Go Ask Your Father” on Relevant Radio, weekdays at noon, either on the radio in her city, or on the internet at www.relevantradio.com.  She will learn a lot about the Catholic faith, and over time, her questions will be answered and her misgivings will be solved.