My best friend ( Nona )

Nona is my best friend ever , I really love her , I  met her 5 years ago( if you met her only which is your case)/ i had known her 5 year ago( if you had known her since then).*(if you use ' i knew her 5 years ago' it means you knew her 5 years ago and went on seperate ways i.e.  you don't know her anymore.)

In the beging(begining) I hate her but when I talked to her I got to know her characters .

I consider(if you use 'considered' it means you don't consider it now) her like my sister , she know everything about me.