My mother was diagnosed with early onset AD at age 52, what are my chances?

My mother was diagnosed with early onset AD at age 52. She is of full Italian decent. She is now 65 and advancing very quickly.

Several years ago, I began taking extra vitamin B6,and B12. I exercise several times a week, am always learning new challenging things and have been a vegetarian for 27 years. I am now 42, healthy and with a positive mindset. What else should I be doing since early onset AD is genetically linked. Should I look into Lithium? Other vitamins? Genetic testing? Any advice is appreciated as I have 2 young children and want to be there for them for a very long time. Caroline