Nice! Very pretty! I really like many of the things going on in the first pic, but the main flower is too close to the edges for my taste and there's a bit too much black in the upper right. I'd love to see the whole framing shifted a bit more down and to the left. I like that we're looking right down into the main flower because that kinda pulls me into it and I love the repeating shapes and textures of the other white petals of the flowers behind. The second picture is too centered for me. There's a tug-of-war going on between the central flower, the out-of-focus part in the lower left, and the cut-off flower in the upper right. This one needs a little work. The third picture is much more how a centered flower ought to look, in my opinion. It's cropped a touch too tight on the right side vs the left, but...eh...that's just being picky.
Overall, I think you've picked the right aperture for keeping the majority of the flower sharp while throwing the background suitably out of focus. That's a lot harder than it sounds. Your last pic is what I call, "A swing...and a miss." I agree with you that there's some interesting light going on here. Since this is your wife's flower bed, this is a situation where you could check your watch so you'd know what time the sun is throwing the shadows in this configuration. I could be wrong, but it looks like the strip of light that is just above the flower might be a bit wider than the one that's on the lower portion, so maybe you need to come back a half hour earlier or so the next day so that you could catch that wider band of light as it moved across the central part of the flower? Just guessing here. However, the point is that whenever you run across one of these near-miss situations...check your watch and try to figure out what time you'd need to be there to have the sun where you need it. Then...come back!