You’re always welcome to be part of your newborn photo shoot and those early days family photos can be ones to treasure.  In terms of what to wear, I recommend keeping clothes plain and neutral and coordinating tones if you’re both going to be in the images together as it will give you a nicer feel to the the finished images.   It’s worth bringing along your chosen outfit to change in to (I have a changing area) as the studio will be really warm so you might be more comfortable in something else whilst you are watching your images being created. Here’s an article you might find useful – what to wear for your newborn photo shoot.