P.M.
It's really common for poop training to come later, sometimes by several months. The sensations are different, more effort and time are generally required, it often includes some amount of discomfort, either from the movement itself or from sitting long enough to finish the deed (toilet-seat pressure and/or tingly legs).
And while the urge to pee is hard to hold back once it hits, the normal peristaltic action that helps push out a poop is very easy to disrupt with just about any sort of distraction, just as normal breathing is very easy to disrupt when there is emotional tension or excitement. And not even all adults can 'produce' at will – I seldom can.
So be patient. She might get the most success if her BMs are pretty regular and you can put hier on the potty when she's most likely to have a bowel movement. Keep it relaxed, maybe read to her, and if she's 'tried' or sat patiently for several minutes, let her go play. She'll get there eventually.
Since she'll put on panties for pooping, suggest instead that she put on a diaper instead to avoid the laundry problem. I've known several families that allowed their kids to use diapers exclusively for pooping. They had no problems with the kids getting confused or regressing. The children just had more time to figure out the connections between sensation and 'outcome,' and when they were ready, they happily used the toilet.
