Sounds like you have skipped a lot of content.
So, Evelyn has gone, did you go the healers house then, did he say she had gone but left her backpack?
Did you then get her backpack and enter her house where her diary and a reveal spell are found?...
Which when you read the diary it puts a marker on your map for her laboratory, and at the location you read the reveal spell to reveal the entrance.
This portion of the game leads you very well in where you need to go.
Check your journal. I get the idea you don't really read anything in the game though.
