I need advice

Needing advice financially... Someone in my family knows about my money & is trying to take it for her self how can I stop it ...she basically knows some stuff to my personal account but how can I make sure she can't swipe it away because my kids deserve that money.. all she wants to do is play with money that ain't hers .. or at least how can I catch her doing this to me so she'll wind up in jail this is the last time she's fking me over .. she's been really wanting to make my life miserable ... She got away with something really bad she did too me & I'm going to make it's her last time to ever think she pull this sh*t on me ... I need advice of how can I hide that money from her if she going thru my mail looking for my sin number or information also I do share a mail box with her ... Her son does know how to hack into people's phones also