The first looks quite cool to me (colour temperaturewise, that is), so to flatter her more, I'd surely warm it up a little by shifting the colour balance over to more yellow/red. Do it subtly, but it will help the photo, I am sure.
The second is funny: her face not only looks so much brighter than the rest but also yellower, in that part, the photo seems to leave the realms of black&white, and I don't understand that! How could it happen?
The third is not composed too well: a lot of headroom, but the frame cuts off her bottom.
And I'm not sure about her pose in the last, as at our age (I'm about the same age myself) we tend to show double chins when we look like that, and I'd HATE anyone to take my photo with me looking back over my shoulder. But if she likes it ... then all is good. I, however, feel that this pose is more one for the younger models.
All in all, watch your backgrounds when you do portrait photography. While these might have been only just test shots in the garden, you might want to do some "serious ones" later, and for that I'd suggest you really go hunting for a nice location. Where there are no rose bushes growing out of her head, no fences in the background and no black plastic buckets and neighbours' houses to be seen.
And yes about the use of flash (though that is a "science of its own" and I am miles from getting even a proper GLIMPSE about the right use of flash!!!).