eh, to be honest, that's how my dd was, and at the same age, and I used bribes and naked time.
I bribed her with her "currency"--candy. At the time she was big into jelly beans. She got one jellybean for peeing on the potty. Worked like a charm, and after the first few times we got a hit ("You peed on the potty! Yay! Here's a jellybean!") she knew that peeing = jellybean and I left it up to her to remind me. After a few weeks, when she was initiating all the time, doing fantastic, always dry, etc, I started putting off the jelly beans--5 minutes, 10 minutes, then I started forgetting them entirely. At first she would remind me, but the time between peeing and reminder got longer and longer until finally she forgot altogether.
Different kids have different currencies, though. I've heard of chocolate chips, chocolate milk, strawberry milk, a small cup of sprite or ginger ale, stickers...anything that the kid loveloveloveLOVES and is willing to work for.
This started when she was 22 months with her poop training herself. It took just a couple more weeks for her to be naked-trained (if she was naked from the waist down, she was totally trained) and maybe two months before she was completely day-trained--so she was about . I waited to put her in underwear until she was 2 yrs 3 months though because we were moving and I didn't want to deal with it.