Emi is the best Airbnb host you can meet nowadays, very helpful and I enjoyed chatting with her a lot. Her place is tidy, cosy and artistic, also located at the perfect place for the old town, beach and city centre (basically everywhere).
Emi also provided some useful books and maps about San Sebastian, and I must mention that 100 pintxos book. If you don't know what to do after enjoying the sunshine, just following that book and Emi's local guide, go to the old town, then eat as many pintxos as you can, which is the best thing you can do for a holiday.