I started with my daughter at 18 months, and she was done (including night) by 23. (90% of all kids trained by 18 months prior to the 1960s)...There is no such thing as "too young." You daughter sounds very ready, so get her to the potty! This is what I did:
Every morning, we spend 30 minutes playing with the potty, i.e. reading books, etc. I would end ever session by going to the bathroom myself. I would also put her poop in the toilet and have her flush it, telling her "pee and poop" go in the potty. They say that after 12-15 hits (pee in the potty), they understand "control." And it's true, once she started going pee in the potty daily, within a week it was 90% of the time. I then put her in trainers and put her on a schedule (teaching her potty etiquette, you go pee first thing in the morning, before you leave the house, etc). I kept her in cloth diapers for nap and bedtime, but she was dry at naps.
We had lots of little regressions but after each she made a giant leap forward. Three things I wish someone had told me:
1. praise works the best. So develop a potty dance and when she has a success, throw her in the air and dance around. Then call daddy, and gramdma, etc. If she starts to show resistance, grab some stickers, but only use them as a last resort, i.e. you are out to dinner, know she needs to go and she is in her trainers!
2. Be patient. Never show negative emotion. When she has an accident, just say "pee goes in the potty," and/or ask where pee goes.
3. Never ask her if she needs to go, instead, give options that always lead to the potty: do you want to go to the potty before or after snack, do you want to go on mommy's potty or on yours? do you want to go before mommy or after mommy? When my daughter showed lots of resistance, I would then ask," do you want to walk or do you want to be carried?" Then DISTRACT, DISTRACT, DISTRACT. The questions give them a sense of control, and then, if you start asking them about something else, all resistance barriers come down.
4. It takes them time to take themselves off to the potty. They are young and easily distracted. At 25 months, my daughter is finally always telling me when she needs to go. She has done it sporadically from the start, but it literally took 7 months to get to that place where she just takes herself all the time. I read that this is very, very common, especially when they are young. So, having a schedule is very important.
5. Once you decided to train, don't turn back. You having confidence in their ability is 50% of it. If you believe they are a big girl, they believe they are a big girl. So, once you go to trainers, do not put her back in diapers during a regression. Yes, it's a pain in the butt, but worth it in the long run.