I would recommend checking out Katy bowman’s website, Aligned and Well. She has great info for DR. With 3 finger you may not get it to come back together all the way but may see improvements. I would not recommend wearing the splint.
Good luck. I know how hard it is with lots if kiddos. I homeschool my 4 but I do manage to do the alignment exercises at least 4 times a week and try to watch how I am moving about my day which in the long run is the biggest factor.
Btw doing Katy’s double calf stretch is the best thing you can do for plantars fasciitis