I agree with the opinions above. You have a long femur and the saddle fits your leg.
You might try going into 2-point (at all gaits) for a few strides, concentrating on where your leg is when you hit that perfect balance. Then as you sit back down, keep your legs where the 2-point placed them. You may need to grab pommel and scootch your crotch a bit forward -play with it. Mirrors would help you with the ideal alignment of anklebone, hipbone, and shoulders, and then you simply need to keep on it until your leg is properly underneath you permanently.
You may need to play with stirrup length in the quest for the correct position - your stirrups don't look long to me, but I'm not the one in the saddle. By bringing your lower leg back to align ankle and hip, toe and knee, the stirrups may well need to come up.
FWIW - I noticed that your outside hand is high and more forward in each photo. When the mare isn't too spicy
, you might try bridging your reins to force that arm back down and elbow in closer to your body.
She is lovely and you two fit each other well and make a nice pair