Hi C.,
I went through potty training hell with my daughter right around 2 1/2. Came here to ask for help and heard Moms tell me to chill out, it'll come in time and it's not up to me, it's up to her. Oh I got so ticked off I can't even tell you buttt.....as much as it pains me to say it....every single one of them were right. Now that my son is 1 year I've learned some valuable lessons about potty training which I'll share.
First, your timetable means absolutely nothing to her. She could care less about your agenda and from the outside looking in, I highly doubt you will be sucessful prior to the baby being born. You can begin now if you want but don't expect to be done or near done by the time your new one arrives. We tried everything for a year. Sticker charts, rewards, candy, outings, punishment, yelling, pleading, crying. You name it! Plain and simple she wasn't having it. Then she turned 3. Had her birthday party and saw all the other little girls using the potty. When I put her up on the baby changing station thing and then just calmly told her how she was just too big for this and look at all her friends who are using the potty and then maybe it was the next weekend I told her we had run out of diapers and that she just had to go on the potty and left her alone. Lo and behold she trained immediately and I can count on one hand how many accidents she had and that was in March.
She'll get it, start instilling the lessons now. Let her watch you, take her to buy some of her favorite character undies, keep it fun, praise, praise, praise and just accept the fact that it's unlikely it'll get done before baby #2 comes.
Good luck and congrats on your impending arrival!