I actually would suggest that you talk to your DENTIST, not the pediatrician. We go every 6 months ourselves, so I just asked him what he suggested we do (or not do). He was the first one to advise me to get rid of the bottle (at age 1) and then the hard tipped sippers (as soon as you can manage without them..).
But, until you can talk to a pro:
Even if she had no teeth at all, you would want to use a piece of gauze to run over her gums each day (or night- preferably just before bed) to help remove bacteria that grow on any leftover food particles or sugars from milk/formula/juice, etc.
But, I'm assuming she has a few teeth (mine had 8 already at that age). With our kids, we just required brushing at bedtime (so they didn't go to sleep and let their teeth bathe in all the sugars in their mouths all night long). When they get older you can begin having them do it in the mornings too - this is almost just a breath freshener... and you will know when they need this! LOL
Be sure the brush is sized for her (if it is too big it can be difficult to use properly without hurting her lips/gums) and is soft. That was the biggest problem I found with the kiddie electric ones... the bristles stick out too far (b/c of how it's all put together) to use very well on the outsides of the teeth.
You can use infant toothpaste if you want, but it's not really necessary, especially if you have city water that is flouridated. She might like it b/c she sees you put something on YOUR toothbrush. The most important thing is just gently brushing the teeth and rinsing with water. (That was my kids' favorite part.. swish with water and SPIT in the sink!!) If you want to use your regular toothpaste, be aware that swallowing it can be harmful and that the taste is usually stronger than little ones care for. And beware, spitting is a skill that has to be learned and she is probably not ready for spitting just yet, so if you DO use paste, don't use much at all!
I wouldn't make a big deal out of it.. just maybe include it in her bedtime routine. If she isn't fighting it, it shouldn't be an issue. Our daughter always loved doing it.. our son-fought it like his life depended on it and it was a major ordeal for me nightly. (sigh)
Just try to find a toothbrush she can manage on her on. It will be awhile before she can actually DO the brushing and have it actually accomplish anything, but as long as she is playing at it, that is great. Let her have her brush in the tub if you want. Get one with a big fat gushy handle in her favorite color, or with her fav. character on it, or one that lights up. They actually have one that blinks for 1 minute (or whatever the recommended time for brushing is).
Just try to enjoy it... you basically have to do it for her until she is at least 2 1/2, and then I'd let her have a go at it, then you follow up after her until she is close to 4 or so. Your dentist can advise you. She should see a dentist around age 3, I think it is.
oh, one other thing.. do not to let her walk around with the brush on her own! It might look cute, but it can be dangerous. You don't want her falling with a toothbrush sticking out of her mouth!
P.S.
We do not use a "pediatric" dentist. Our family dentist is not one of the "medical-clinical- no personality" types. He is very "fun" to be around, just a bubbly personality, and has kids of his own, so he is GREAT with the kids! If that is the kind of dentist you have, then I wouldn't look any further. My 7 yr old was excited to go to the dentist, she enjoyed being the center of attention!