But your edges don't look thin to me. I mean, I can't see them in person, but your edges look pretty fine to me! They actually seem to be pretty thick and definitely not receeding.
I'd say def relax edges last if you aren't already doing that and massage them with some type of oil like Jamaican Black Castor oil or some stimulating essential oil (rosemary,peppermint,etc). Also keep them very moisturized so they don't get dry and break off.
it came out really cute!!
i don't really see much thinning, but rubbing castor oil in mine every night def keeps them nice and full.well, as full as they'll ever be.
As for your inquiry about the edges I'll pass on a tip I picked up from African Export (YT). She put satin rollers on the ends of her twists to also give them curl. I don't see why this method wouldn't work on your braided ends. I'm sure you could use flexi-rods or perm rods instead if you don't have satin rollers....hth