Yes,you can get this with gaussian blur (I guess 10 or more),make a mask and selectively paint around her.See that edges of her head is also blurred.
Lower aperture values in camera, but if you're using Photoshop CC, filter -> blur gallery -> iris blur. just make sure that everything on the same plane has the same blur or it'll look weird.
Thank you so much, will have to try. I guessed it was some kind of selective blur or softening plus the grain. I always loved grain on blurry areas. I'll have to try different things. if anyboady else has any other ideas or tips, share please. Thank you all.
for the grainy look, give this a go. in photoshop create a blank layer on your image and fill it with 50% grey and change the blending mode to soft light. then turn that grey layer into a smart object. the go to filter and add noise. 8-10% is a good starting point. make sure it's monochromatic and the distribution is gaussian. the go and apply a light gaussian blur to the layer (0.2-0.3). that should give you a nice grain look. as it's a smart object, you can always change the values to taste.
Thats the "old" method. I did this myself for some years. New one is instead of "add noise and blur" to the grey layer, use Filter -> Camera Raw Filter -> FX Effects Tab -> Grain. The Camera Raw Filter-Grain is much more organic than the "add grain+ gaussian blur" method.
You can create most of it in camera, shooting it at a shallow depth of field (mostly 1.8-2), use a tripod to up the success rate of your shots. if you are shooting in a studio its important to have a light which has HSS feature in order for you to use shallow depth of field, if not you can use ND filters to compensate for that. for outdoor you can shoot some partially backlight shots. how to create this in PS other people have covered it well . but if you want to do in camera it will give you some awesome results as blurring the image in PS, i dont like it that much. Cheers!