Hi and welcome Disey! It is certainly doable. If your partner is not able to drive herrself ( for example health reasons ) there is a company called Marly Tours that does the driving and arranging. Don't find the link now but am sure other forummembers will give advice.
Public transport is pretty ok. So your partner could take a bus in between the bigger cities, spend some extra days here, arrange an hotel or pension there ( nice for you when you arrive ). Or if he/she wants to meet you every day they could take a taxi in between every village you stop. In that case they could end up in really small villages where there is nothing much to do of you are not a pilgrim.
Also take into consideration that public albergues or donativos most probably won't take in people who did not walk that day. So private accomaodation might be best.
Pamplona, Estella, Puente la Reina, Logrono, Burgos, Carrion de los Condes, Sahagun, Leon , Molinaseca or Cacabelos, Sarria or Portomarin and then of course Santiago or excellent towns to stay a couple of days.