most of my friends who tried sk2 mentioned it was good.. in fact so far i did not hear any negative response abt it. in most cases should have improvements to certain extent, at least it wont worsen the skin. generally sk2 suits most asian skin types, u could just go to the counter and describe ur mother's skin type to the sales, and maybe some particular treatments tt u want to buy for her, such as eyes, skin refining, or anti-aging, etc.. think the sales will give u good recommendation.

just a suggestion if u really want to choose a branded and good one for ur mother. :)