I have a few comments, in no particular order...
- The blurring/shallow DOF is bothering me. If the eyes were super sharp, it would not bother me, because it would appear intentional and stylish, but because they are not, it does. And it does give them a ghostly aura.
- The eyes. This is my biggest issue - babies' eyes need to be clear and sharp. Your first is the best at that. A little editing could help the others, to some degree, but it won't remedy the situation entirely.
- The color. I'm fine with the pale color, but I prefer it on livelier babies. On sleepy or still-looking babies, I do think a little more color is nice. I don't think they look spooky, per se, but if other people do (and they obviously do) then it's something to consider. I realize that they have very fair skin and my second child had that same almost translucent skin - there's only so much you can do with it, colorwise, since upping the saturation often doesn't help. I resorted to a lot of B&W when I wasn't pleased with his skin tone. I do think it would be less of an issue with sharper shots which would bring down the ghostly factor by several notches.
- The cropping. I think the first could do with a slightly tighter crop. The last one is great. The middle crop isn't really working for me.
I think they are sweet photos and I'm sure their parents will love them, but those are just some things to consider for next time.