how can i stop her from biting

Question
QUESTION: hi i have a 12 week old sheltie/bluehealer mix and she still goes in the house even though i take her out every half an hour to an hour she will do really good most of the day but then she will start going in the house towards the end of the day what should i do

ANSWER: Twelve weeks of age is far too young in most dogs (there are exceptions) to expect housetraining skills to be set.  You're doing very well with your efforts and you need to keep going.  I suggest you lengthen the time to 90 minutes after her first two morning outings and decrease the time at the end of the day when she seems to need to go out more. You might want to observe how much water she drinks and pick the water up about 7:00PM, providing she's had a sufficient amount.  Reward with praise (lavishly) when she eliminates outside; IGNORE (or interrupt by clapping hands without looking at dog) if she eliminates indoors.  She WILL get it.  Putting her on a lightweight nylon house leash toward the end of the day and closely observing her might help you get her out in time.  The breed combination makes for a smart dog that wants to work for you.  Hang in there!  I expect pups to have occasional "accidents" as old as 9 months of age and sometimes beyond.

---------- FOLLOW-UP ----------

QUESTION: the house training is going good but now another problem i am having with is that she is biting now i have been told that biting them back on the ear helps i was just wondering if it does or if i should go in another route

Answer
That isn't "biting", per se, it's part of the teething/rank development.  Puppies learn that using their teeth hurts by the reaction of litter mates.  If a pup has been removed from litter mates too soon, or bred in a situation where normal development is negatively impacted by environment, the pup does not learn that using teeth HURTS.

The first defense is to demonstrate pain.  YELP! as loud as you can, and turn away from the dog, count to ten, turn back.  If the dog persists in using her teeth inappropriately, get up and move away, then return.  If she still persists, get up and put a closed door between you, count to ten, go back in.  At the same time over the next days, teach her (using positive reinforcement training) to perform a behavior you can REWARD.  A "sit" is very easily trained.  Take a treat, hold it up over the dog's nose, she will naturally go into a sit posture.  Choose a word for "sit" (any word, just not "sit") and pop the treat into her mouth, saying the word, the moment her butt hits the floor.  Back up, holding another treat; dog will follow.  Hold treat over nose, repeat as before.  Do this three times in a row, then quit.  Repeat the training exercise 5 to 10 times a day, keeping it short in duration (no more than 3 minutes at a time).  By the third day, she should have a conditioned response to the word you've chosen for "sit".  Just be sure the dog's eyes are on you, say your word, when she sits say "GOOD" and throw treat or pop into her mouth.  After 30 repetitions you have a solid conditioned response to your word for "sit", just don't test it across a large room; being able to "command" a dog from a large space requires time and maturity on the dog's part.

Now you can "command" your dog to "sit" when she begins to use you as a teething ring.  She mouths inappropriately, you yelp and withdraw, then turn back to her and give the word for "sit" and reward.  This dog needs to EARN EVERYTHING, she is very smart and independent.  Once she learns the "sit" command, make her earn her food, her walks outside, her games with you, being petted or interacted with.