You should always work from a photo reference when you first get into painting. Have to build up a mental inventory to draw from. The rendering on this painting isn't bad, but the composition and anatomy need further development.
Also, it looks like that cat just ran full speed into her ass cheek ;P
the concept is great and the cat!! the girl is getting there but needs help in the hip area, the top hip looks very squared off and her shoulders look very wide to me... the ref comment is a good one, they help a lot. looking very good though a bit dark but could be my monitor?