Stupid friends

Omg...okay I have a problem, theres this friend, like shes my bestest friend-I luv her!!! But not like that, anyway thats not the problem...this is... Okay...sometimes she can be really really stupid like she has no common sense... What should I say to...

tell her that sometimes shes really stupid!

say no offense but your really stupid!!
haha jkjk
just tell her thats sometimes she makes no sence but you luv her anywayz lol

'Sometimes it appears you judgement is a little lacking - do you want me to let you know or just stay quiet ?

say like, did you really mean that
and if she really does, well then she oviously isnt knowldged enough
so theres no reason to be mean about, shes just a little slow

thank all of you guys for the advice it might be really helpful