Tyger sketches

[Samszym]

I think your absolutely right about needing to pick the scene you're going for, I think it would be much easier for you if that had been the first thing you did! Once you decide on what the emotion of the piece is you'll have a standard to help you make decisions about the pose and the composition and everything else.
I still don't think you should be looking at photo reference yet, to me working form a photo from the beginning seems very limiting to the imagination. Really figure out the emotion in the posing and then bring in the photos to make it all look real! See what happens if she's leaning forward to be closer to the bird, or maybe raising her arm above her for the bird to perch on and giving them a more dynamic relationship, or maybe her and the bird are a lot more vertical and stable and at rest. It all depends on what emotion you want the scene to be showing.
I think your reference and sketches right now suggest she's sort of scared of the bird and that it's going wild, maybe getting ready to fly off. To get the mood you want I might draw it right before it lands, and to show it's landing emphasize its feet more than the wings with value contrast and really clear silhouette.
Hope that helps, really looking forward to seeing this piece as you move on, it;s really nice to see how much thought you're putting into it!