Well, Dancer isn't standing well, for starters and that's making her look worse than she really is.
I've marked some corrections for you :
Even in this stance I got a shoulder slope of 54 degrees (which is steep, but not really critically so, and steeper than reality because of how she's standing) and an angle of 84 degrees (or so)... which is not that far off of the 90 degrees we seek, so while it is technically a closed angle, I'd like to see what it actually looks like with her front leg squarely under her body before I wrote it off. Your point of elbow was a little off too, making the angle look way worse than it really is.
The next big problem I see here, is actually where you have her LS, and Point of hip
I got 2.67cm for her hip length vs a 7.28cm body length. That's about 37% of her body length, which is a good length of hip. I got 2.3cm for her femur length, and 2.3cm for her pelvic length - so, even with her standing poorly behind, she's showing a pretty balanced hindquarter.
I got a back length of 3.2cm, which makes it about 44% of her body length, that's a nice length of back. Her ribcage length is 3.36cm... so it's more than equal to her back length - which is great, she has a short loin. Her LS placement is good too. She has a very nice deep loin girth.
What I wonder, looking at this photo is if she's pregnant? If she's not, I'd get her an aggressive deworming "program", as her stomach (if not very heavily pregnant) is showing some digestive distress. (I don't actually see a "skinny" horse looking at her... to me it looks like a wormy horse - a big barrel, decent fat covering, but still ribby)