One technique I have learned recently to read the exposure correctly is that they first go very close to the subject's face to fill the frame mostly with her face, then they set the exposure. Then they go back as much as desired now that exposure is determined and now they focus and take the picture. Since I am using a manual lens my question is do I also need to be in sharp focus when I get close to just meter the exposure?
No, exposure is not much dependent on exact focus. Metering close to the face is exactly correct for incident meters (which pros likely use, to read the actual light there at that spot, but the incident meter is aimed away from the subject, towards the camera.)
But reflected camera meters will underexpose Caucasian light faces, about 1 stop. Reflected meters expect a more middle gray scene overall. When spot metering on a face, we must know to increase exposure about 1 stop. How light meters work: http://www.scantips.com/lights/metering.html