It's not easy to pick clothing for the entire family for a photo shoot. I get it. I've attempted that before with my family of five. I've taken pictures of families at large as 7-8 people. They all looked wonderful, no matter the clothes. But it is very important to think through this before the session. Truthfully, choosing attire for your family session is complicated, but giving advice on it is also very hard. Only you know your family style, preferences of your teenage children, grandma's selection of holiday-themed sweaters and how it all ties into the scenery or studio background of your choice. Here's a short list of what I can say confidently. Whether you use some or all of it is up to you!
And remember, it’s not what you wear, it’s how you feel in it. If you feel happy, it will show, and that’s all that matters!