my gf is from Philippines, but working in Korea, can she get a tourist visa to Sri Lanka from Korea? how?

Answer 1

Try at the enclosed link.
Call them and see what is needed.

Answer 2

If she is a Philippines passport holder, she can enter Sri Lanka as holiday makers / tourist without prior visa and remain 30 days without a payment.

Bona fide tourists from the countries listed in Schedule 'A' are permitted entry upon arrival in Sri Lanka for 30 days stay. No further extension beyond 30 days is granted until further notice. However further extension shall only be considered with valid reasons. Those who visit for purposes other than holiday should obtain prior visas.