How can I best display large family photos in ornate frames?

How I wish I could give you a big hug to let you know that you don't have to do what's popular. If you like your children's photos in an ornate frame, then display them proudly. If you'd like to make a change then perhaps one of these ideas will inspire you - https://www.homedit.com/25-stylish-ways-of-displaying-your-family-photos/

I remember that era well. If you love them, then display them! Michelle has some great ideas too. Don't let popular trends dictate what makes you happy in your home. Personally, I love visiting friends homes that have tons of family photos of any kind, it tells a story and fun to see. Celebrating family and friends is always in style in my opinion regardless of how you choose to do so.

I think this is a matter of individual taste. Perhaps you could put them in a large album and set of your coffee table. https://www.amazon.com/Pioneer-Jumbo-11-75x14-Scrapbook-Sheets/dp/B001VGBYCU/ref=sr_1_5?s=arts-crafts&ie=UTF8&qid=1536509192&sr=1-5&keywords=book+for+old+photos

maybe considering creating a gallery wall with your favorites?

https://www.burlapandblue.com/2015/04/20/how-to-create-a-gallery-wall/

I think you should do what you love even if it is popular or not. That's what turns your house into a home. I wrote a tutorial on how to print and hang large portraits/images to create a gallery wall. Maybe this will help give ideas on what exactly you want to do with your photos. http://withinthegrove.com/printing-poster-size-images-for-a-gallery-wall/