First off, there is nothing you have done wrong, Don't worry!
It sounds as though you have given them the best chance possible, scatter feeding, two of everything etc. You have done everything you can, it's just wether they will get along with each other.
If they are sleeping in the same house then it sounds as if Puddle hasn't completly rejected Raindrop, and as there is no biting perhaps it is just a little squabble; If they do start to make seperate beds don't interfere and leave them to sleep where they have made beds. I would just keep an eye out for any biting or signs of injury. Also make sure everytime you handle them they are both being handled, so they both have your scent on them and there is no arguments or jelousy.
Hope that helped, good luck and just keep an eye out!