We are also in the throes of potty "training" of late. The technique we use is to put Adeev on the potty every morning when he wakes up and every night before bed. This has become part of our bed routine. Potty, brush teeth, PJs, story, bedtime. We also ask Adeev once in a while if he has to go, so that he knows that you use the potty at different times of the day, not just at night/morning. We don't have rewards per se, we just give him our undivided attention when he is doing his business - we sit in the bathroom and read or talk with him. Otherwise, we have been doing the poop flush for a while now. Whenever we can flush the poop, we do and we all say, "Bye-bye poopy" ceremoniously, LOL! I am not forcing the issue and if we continue on like this for another year, I will be fine with it. He doesn't feel pressured to use the potty, but he knows that he is a big boy when he does.

It sounds like you could incorporate the potty into Sarah's routine without much fuss - she likes the flushing and seems to get the idea. You might be surprised at how interested she is, if she is already making comments that she pooped. If it doesn't work right now, don't be discouraged - we are all potty trained eventually!