Make up..

Tricky one! If I were you, I'd do some serious thinking about how it is going to impact your friendship if she drops out last minute or if you are not happy with the look that she gives you. I think it largely depends on your characters - if she is a very chilled and reliable person who is unlikely to decide last minute that it's too much for her, and if you are someone who just wants to look 'ok' and is not fussed about having an exact 'look', then you should be fine. But something else to bear in mind is that many professional people will have a backup they can call on if they are suddenly unable to work for some reason (e.g. serious illness or injury) whereas you won't have that same backup if it's just a friend. So maybe work out what your backup plan would be.

If you do I think you should have a girls night together where you can try out different styles and looks as a bridal party. You could do a spa like evening as well to rejuvenate your skin afterwards. And then you will know your perfect look and your friendship will remain intact if you don't want to go with her as your make up artist.