Question

is it proper for u to stay away from your best friend when u saw her doing wrong

Answer 1

no ,if he/or she is doing wrong we have to give advice to don't do 

Answer 2

no its not proper to stay away from your best friend we should advice them and we  should say its not a correct way what ur doing and we should say which is correct and if we stay away then they wil not realise there mistakes by there own and a best friend wil not see his/her friend going in a wrong  way