No matter what the reason, please do not wait and hope the problem will just go away. Although she may start out suffering from illness or anxiety, her behavior can quickly turn into a habit if left untreated. Unfortunately the result is often making the cat a strictly outdoor pet, or getting rid of it all together. That's why the best way to curb inappropriate elimination is to begin treatment as soon as you see the behavior developing. There are a variety of reasons why a cat would decide to use a corner of your bedroom instead of her litter box for her toiletries.
Cats are very susceptible to stress when things change.
That can include a new family member moving in, a move to a new house, a death or divorce in the family, the addition of a new pet, new furniture, etc. You will also need to find out if the cat is spraying urine to mark territory, or if it's just squatting to urinate in a new location. Many cats begin marking as a result of sexual maturity. Spaying or neutering by about 6 months of age cures most cats of this desire. If the cat is neutered and is still spraying, he is trying to let other cats in the household know that this is his turf.