I am not going to do that btw.
But MiL (she is lovely and I have no gripes about her generally), has an unfortunate habit of giving poor dh the old 'I don't need anything, I have 3 beautiful grandchildren, buy what I want when I want to etc. etc.' spiel at christmas and birthdays. He is left clueless as to what to get her and I end up buying chocs/ flowers/ cooking a meal.
If she genuinely doesn't want anything but really wants to have a nice time with her GC then she could say so. Equally she could say well I really like are Boots/ Body shop/ Jo Malone bath products or whatever. But as it stands if we acted on her verbal instructions she would end up with nowt and then give dh and I a hard time for it (well act wounded anyway).
Just tell us what you want woman - she could even say she wanted a 'suprise!' I could work with that!