E.,
First, I have four daughters the first 2 are 21 months apart
the third came 22 months later and the forth 30 months, they were all potty trained long before the next one came. So I really don't believe there is too early...I started with the
bowel movements, mainly because it was usually very apparent
what they were doing, I would take them to the bathroom remove their diaper and hold them on the regular toilet it was amazing how well this worked, my kids never had a little potty, I did not like the mess of it. You can also like someone else has mentioned, if she wakes up from her nap and is dry, take her immediately to the bathroom and let her go, but you have to stay with this once you start, you have an advantage that you are expecting so you are most likely getting to the point when you will have to go more often take her everytime you go, she probably will not go everytime but you are developing a habit. I don't think making everything a game is the way to go, but giving them a "good job" and acknowledging the fact that you are pleased with them when the have accomplished "the task" will go along way, kids want
to please their parents, most of the time(lol). Be patient and talk to her and you will diaper free soon, well at least till July. I do agree some kids regress when the next one comes, but I think it has to do with the moms now having a to split their focus with the new baby and sometimes forgetting to remind the older one if they have to go, it is a constant reminder for a while, and even sometimes when they say no, take them anyway if you feel it has been awhile because sometimes they really need to go but just don't want to take the time. I also found that using training panties, not pull-ups worked better during the day because they feel the pull-ups are just like diapers and can go in them, it is messier but less expensive. Good Luck with Phoenix and with your new bundle of joy.