She's not a 44-anything. She's a slender woman, possibly quite tall, so her bra size is likely to be a 34. She has large breasts, as you rightly point out, If they are an F-cup, her bust measurement may be around 40" when she is wearing a bra, although if they are bouncing the way you describe, maybe she's not wearing one.
That 44" estimate of her bust circumference is sadly a fantasy. A 44" bust measurement on a slim woman would indeed be huge and would stick out a long way in front.
Not that any of these estimated numbers make the slightest difference to the size of her breasts. They are just as big as they look.
The dog isn't looking at you personally, by the way. He looks at everybody like that.
