We set a timer for 45 minutes, then 1 hour, then 1 hour and 10 minutes. We used the oven timer which was loud enough for us all to hear, and she couldn't reach it. I would set her on the potty and she went, and couldn't get up until she peed. I also found some things for her to have only in the bathroom. We set up a tv tray thing for her to use to do a sticker book or whatever on so that she was comfortable enough to sit for a few mintues at a time. The first 3 or 4 days were hard, because she kept getting down even though she hadn't done her "business", so we just kept putting her back on the potty. Once she understood that she was in the bathroom until she went, she did her thing and moved on.
A tip - Don't watch, stand out of sight and listen. My kids are funny about this, so I stand outside the door.
Also, if she is waking up dry, then she is ready to potty train, and if she can't hold it through the night, she may not be ready yet.
Good luck!
-C.