It is usually advised that the bride have a trial before the big day with the wedding make up artist.
This means they can go through different key make up looks, discuss colour schemes which may be tied in to make up colours and guarantee, most importantly that the Bride is happy with her final wedding day look.
On the day, a wedding make up artist will arrive with a full make up kit. It is common, if there is a big bridal party for the Wedding make up artist to start on the bridesmaids first and then make over the bride in between and maybe re- touch just before the bride leaves for the ceremony.
You want the bride to look as fresh as she can!