She's smart for applying coconut oil, she can also take a spoonful daily internally to help improve the skin.
Years back I also was getting similar red marks on my skin, and I never went to a doctor, so I didn't know the real cause. But they were dry feeling also.
I started to take a good quality omega 3 fish oil, and that really seemed to help. Here's more on the coconut oil, it's good for various skin conditions such as eczema, etc.
https://www.natmedtalk.com/wiki/Coconut
I also see nothing wrong with using colloidal silver to treat it. The only brand I'm familiar with is Mesosilver. By the way, welcome to the forum, glad you stopped by!