DD will be 25 months when new baby arrives (18 months now). She tells us when she needs to pee and poo and is very interested in the toilet when I go. Before I got pregnant I was planning to start around 20 months and see how she got on. But with new baby coming I'm not sure what's best. I don't want to delay just because I'm afraid of regression is she's keen. But I also don't want to deal with accidents at the same time as a newborn! Thoughts?