hi sis as much as possible it would be better that u can send loads of evidence of ur relationship so no way for the ECO to deny ur application..
I remember when I am also preparing with my visa, I have sleepless nights printing our chats and emails, good thing is he helped me with our pictures..
we only got a few snail mails because we used to chat and send emails to each other for almost everyday and we hardly call each other on the phone but luckily I got my visa..
so dont worry about it sis, as long as u provide much evidence for sure u will get urs also soon..
Goodluck...
