Vinegar is the cure to urine-scented items - Put a cup of distilled white vinegar in the wash - or diluted vinegar water on carpeted areas that have that scent, and wa-laa, smell is gone.
I don't have a 13 year old with this problem, but a 6 year old who was wetting frequently most nights. I finally went to the doctor and thought it was maybe a surgical problem. He told me that it is a more common problem than I would think, and to try using a bed-alarm. He used it with his 12 year old, and it worked wonders. I purchased and have used it with my child and it completely solved the problem within a couple of weeks. Look into it, as long as your daughter doesn't have a medical issue, it is well worth the 70-80$ I paid for it, and worked so great. My child feel so much better about himself now; That must be so hard for you daughter to still be having this problem at 13, I hope you get it figured out! Good luck!
How the bed-alarm works: It is a moisture sensitive pad that gets placed in the childs underwear and has a cord attatched to it that fastens onto their shirt. At the first drop of moisture, an alarm sounds, and wakes up the child, (and parents) to get them to the bathroom. The first week, you typically end up racing into their rooms and getting them up to go to the bathroom, the second week, they are able to wake themselves and by the time you get to them you are meeting them in the hall; the third week, their brain is conditioned to awaken before the alarm sounds because they are able to recognize the sensation of needing to urinate. It is basically a conditioning process. It actually went even faster for us, only took maybe 2 weeks.
Also, my doctor prescribed a medication that when taken, they WILL NOT urinate at night. I don't know how it works. He had me give my son a half a tablet about 4-5 days before using the bed alarm to kind of bolster his confidence that he was able to 'stay dry' by himself. My doctor said his 12 year old son occasionaly has the bed-wetting happen now if he is under alot of stress. He uses this medication now very occasionaly on nights he knows his son is undergoing stressful situations. I can't remember the name of it without going through my cupboard, I would ask your doctor if this is of interest to you.