I agree with Doubty
. If you buy things and then practically force her to paint you will completely put her off. Inspiration is not something you can switch on and off like a light. You are trying to force her to paint. To an artist that's almost like rape.
Go at it from a different angle:
tell her you'd like to learn how to paint and ask her for help and advice.
This way you can be sure you get the right stuff, you'll lure her into painting without being obvious and teaching you will make her feel relaxed (contrary to you forcing her hand).
You must keep in mind that inspiration can't be triggered. It comes and goes as it likes. Picture it as a wild animal. You can not force it to come to you. All you can do is invite it to stay by providing nice surroundings for it. And if you're lucky, it'll stay.
(Excuse me being so blunt, but I fear this is the only way I can make you realize what you're about to do: if you keep lacking every sense of tact and diplomacy and keep applying sheer force instead, you will never get any woman, let alone an artist. You're using a battering ram to open a crate of delicate antique china!)