Size of Pacifier and Weaning Pacifier

I would wait to take it away until 2-3 months after the baby is born. That is what we did with our daughter when our son was born when she was 2. There are too many changes and new things to worry about without adding the pacifier as a big change right when baby comes. Both my kids refused to use any new or bigger pacifier so they both used the smallest size until after their second birthdays. I don't think it should be a problem for her teeth as long as you have it gone sooner than later. Good luck and congrats on baby #2.

Yikes probably a bad time to try to take it away from her. She'll just be stealing it from the baby. If you've all ready gone down to paci at bed and nap time only. I think only thing left to do is take it away for good and deal with the crying for it for a coupld of days to a couple of weeks. Good luck!
I'd personally would just wait until she is older and up the size.

Well whatever you do, in the meantime, I would get her a Lovey... to sleep with and comfort with. If she does not already have one.

It will help in the transition.

Next: there is no guarantee, that your next baby will use a pacifier. Not all babies/kids use one nor like it nor take to it.
My daughter never, took it. My son did.
Each kid is different.

I would also, right NOW, talk with her about the 2nd baby. So that, she can adapt, better. Talk with her about it, so that once baby comes home she is not all in shock or has difficulty, adapting.
Explain, that a baby wakes/cries/Mommy nurses him/er.
Get her a doll, too. To cuddle and/or have for herself.

She should be on a larger one for the development of her teeth, that is why they put age labels on them... With my oldest I took it away at 1.5 years old, my youngest isn't there yet. I just didn't give it to him at bedtime on a Friday night, then made them all disappear while he was sleeping. It was like doing "cry it out" for the first night, but by the end of the weekend he was over it.