@Beards Thank you so much. I've decided to give her an iPhone 8 since she will be ecstatic to have a great new phone (you know... girls and their phones), and the camera is a huge upgrade for her and takes great pictures and is always with her in every moment in life. If she outgrows that camera too and decides that she wants to go even further from there and wants to take her photography hobby to the highest level, I'll definitely give her a Rebel DSLR sometime. ;-) For now, everyone leans towards "A DSLR is really nice but we take most of our photos with the iPhone", and the photo quality in the 7 Plus is really good. I'll jump on pre-ordering the 8 for her as soon as it's announced in September!
I hope this thread helps other people in the future.
Personally, I don't think the 7+ photo quality is all that great. My daughter and I both have one and we both think the iPhone 6 took better pictures, especially is low light. And Apple's noise reduction algorithm seems to be especially aggressive.
Having said that, I agree with the sentiment that you can't take a photo with a great camera if you don't have the camera with you.