I'd go to Boots or John Lewis or similar, have a look around and then ask the girls behind the counter. They are very knowledgeable and like nothing better than a 'helpless' man (so my husband says anyway!). Go for the premium brands - You won't go far wrong.
There are lots of nice Xmas gift boxes out.....John Lewis a good start...esteé lauder always do a nice one....sometimes if you buy scent they do a discount package to include cosmetic box at discount....
You need to know first of all what sort of makeup suits her skin - to buy the wrong sort would be a disaster. Far better to book her a facial consultation at a beauty counter in a store - if she's not sure, they would advise.