i saved ivan anderson and defeated the raven they sent to speak with bjorn ironclaws and thats it nothing more then my friend is a lower level and she got to go to ravenscar :
Um... ive only got up to Virgid roughland but here's what i heard.
Gotta be level 20 to go to Grizzleheim and do Saverstad Pass.. yup of course. Gotta be level 25 to do Virgid Roughland..... Ok, Cool. Gotta be level 30 to do.... im guessing Mirkholm keep? Sure. good. 1000 health boss i defeated with my friends.. good before starting marleybone 1001+ healthbosses. Gotta be level 35 to do.. Nildavar...? (im sure i spelled it wrong) And 40 to do Ravenscar. for sure. err... but i wouldnt DARE quest there until i was 48+ because then have have Scarecrow/storm lord/fire dragon/ orthus/ frost giant/ Rebirth. lol. and you got better health and probably defeat malistare already.
Plus your friend might have teleported to a friend in Ravenscar.
I dont know so much if Nildavar is 35+ because my level 34 friend was in it ... at least i think he was level 34....