I found having fabric draped over the body made it more difficult to capture proportions correctly, and foreshortening also required closer attention. I think, even though the figure is reclining in a soft sofa, the right thigh still looks too long compared to the shin. Also the visible forearm and hand are far too small.
Otherwise I like this study, the composition emphasises the atmosphere of a lazy winter Sunday afternoon, of the subject gazing off into the garden, watching the birds through the conservatory window. The fall of fabric joins the subject to the sofa and gives a feeling of relaxation, as does the way her blouse has ridden up around her shoulder as she nestled down.