The lap tray is highly recommended. (Seems to be similar timber) The top makes a very strong impression. As she painted and thus is "slippery", I glued a small, thin rubber mat so that items that have no rubberized bottom, also adhere to it.
The filling of the pillow at the bottom of the tray seemed "a little bit" before, but is ok. You can replace the filling so, if it should not be enough.