First steps commissioned painting of a Saint Bernard

I have currently been working on the starts of a painting. This work was commissioned to me by a neighbor. They recently lost their dog. They are quite torn up over the loss and have asked me to a painting for them to give to their son for christmas. When I asked them for more details of what they wanted as in size or style. They generally have intrusted the decisions upon me. I feel this is a very smart thing to do when commissioning an artist to do a piece. You should always give general preferences, but we have the experties to predict how the piece will look best and know when the piece will miss its full potential. We chose to go with realism as you just can't go wrong with realism. It does take more time, attention, and a different painting approach. They did not seem to want to go large so I have decided to go right in the middle 16"x20" on stretched canvas. It will not be too big but will allow more room to work the details of the portrait. This being a common size will also make it alot easier for me to find a propper frame and eat up less of my profit.  The photos I've been given to work from aren't the best. They are limited and were not exactly taken by anyone experienced with photography. So I looked through them and finally chose one. None of them had in great lighting, postitioning, or great angling on the subject. The one I chose seemed to be the best pose of the dog. The thing I am not happy about is that she is laying on grass. I hate painting grass. It is very time consuming if you dont want it to look rushed, but I will worry about that part when I get to it. I have decieded to exagerate on the lighting and colors in the painting as i feel this is the one thing that can bring the scene to life. I had done a pencil sketch where I worked the positioning and tried to match it up as well as possible. I then painted over that with umber and have just finished the charcoal sketch. I will be starting with the paint tomorow. Here are 2 photos of the pencil sketch with the umber layer over it and the charcoal sketch then after. I have always found it funny the way I draw. I am always very shaky and can't make strait lines. When i draw somthing i just start putting the lines down and correct them with another line until they measure out right. anyways....