There is an easy explanation as to why this happened: Your cat couldn't get to the litter box. When she chose the couch, it was most likely because it seemed like the closest thing to a little box. Doesn't sound like a problem since there is an easy explanation. You might want to replace the cat door or fix it so that it can't get jammed again, OR put a litter box upstairs so that she won't get trapped on the other side of a door from it again. One time won't cause a recurring problem, but do take precautions so that it doesn't happen again!
It is possible she may go on the couch again now that it smells like urine, so if I were you I would replace it ASAP, or at least have it cleaned very thoroughly. Deodorizers usually don't work because although they cover up the smell for us, a cat's sense of smell is much stronger than ours, and they can still smell it through the deodorizer.
If you continue having problems with her urinating around the house, especially if she goes in a different place every time, it could be a urinary tract infection, possibly caused by trying to hold it all day. If you see signs of this, be sure to take her into the vet to be checked out and prescribed antibiotics if necessary, and that should take care of the problem.
There is an easy explanation as to why this happened: Your cat couldn't get to the litter box. When she chose the couch, it was most likely because it seemed like the closest thing to a little box. Doesn't sound like a problem since there is an easy explanation. You might want to replace the cat door or fix it so that it can't get jammed again, OR put a litter box upstairs so that she won't get trapped on the other side of a door from it again. One time won't cause a recurring problem, but do take precautions so that it doesn't happen again!
It is possible she may go on the couch again now that it smells like urine, so if I were you I would replace it ASAP, or at least have it cleaned very thoroughly. Deodorizers usually don't work because although they cover up the smell for us, a cat's sense of smell is much stronger than ours, and they can still smell it through the deodorizer.
If you continue having problems with her urinating around the house, especially if she goes in a different place every time, it could be a urinary tract infection, possibly caused by trying to hold it all day. If you see signs of this, be sure to take her into the vet to be checked out and prescribed antibiotics if necessary, and that should take care of the problem.