I went through this as a child, and my bladder problem eventually had to be corrected with surgery. Definitely take her in to the doctor and see what they say. Her bladder may just need to catch up to the rest of her body, or there may be a more serious issue, especially if she's having UTIs. In the meantime, here's the advice I gave to the last person with this issue:
Don't let her drink more than a couple sips at a time after dinnertime (for me it was around 5pm), and nothing caffeinated past lunch-time (around noon or 1pm). Caffeinated drinks shouldn't be allowed often anyway; caffeine stays in your system for up to 24 hours and can really contribute to the bed-wetting. Sugar also.
Take her to the bathroom at least twice an evening (once after dinner and once before bed), and make her sit there for 5 minutes trying to go, to make sure it's all out.
During the rest of the day, try to get her to go to the bathroom (even if she doesn't feel like he needs to) at least once every two or three hours. She may not be understanding or even getting the message from her brain saying that she has to pee until it's too late, and going this often lets her bladder get used to being empty... She should start recognizing when her bladder feels full, and that will help her at night.
Cranberry juice and water are always the best things to drink for kids with bladder issues, so try to stock up. ;)
If none of that improves her bed-wetting, then middle of the night trips to the bathroom, again making her try for a full 5 minutes, may be in order.
In the meantime, if you want to try any "big kid diapers" or plastic sheets or whatever will make your life easier on the clean-up end, feel free.
The main thing here is to be consistent. You have to come up with a plan and stick to it every day, and every night. I know it's a pain in the a** to get up in the middle of the night every night to take her to the bathroom, but if that's what you need to do, then do it. My mom did that with me for at least a year before my surgery. There may be kicking and screaming and tantrums, but it's all for the best. Good luck!