|In your desire to be politically correct by giving rave reviews to your manager's paintings, you have painted yourself into a corner. This does not mean that you should have asked her if she had any trouble painting over the numbers, but tempered praise would have been adequate.|
Obviously, your next step is not to buy a painting. You can tell her that you appreciate the offer and enjoy seeing the paintings on her walls, but at this point you are not in the market for this artwork. You can thank her again, but be sure that she understands that you are not a buyer. If she goes for the hard sell, or if you see repercussions down the road, you will need to have a more candid discussion with her, and with senior management if necessary.
The larger issue is that your manager has absolutely no business turning her office into an arts and crafts bazaar. She is probably in violation of company policy on this one, as her actions waste time, generate stress, and interfere with the ability of staff to meet departmental objectives. Senior management will not view this an effective display of the art of management. In fact, managers who hustle the employees are often hustled out the door.