Mastered doing wees but struggling with poos!

[gem584848838]

My just turned 3 year old is now in knickers and doing great with wees. She has been in them permanently just over a week with no real issues with doing wees, only a couple of accidents where she's been a bit late with pulling down her knickers when going on the potty.
However, we're really struggling with poos. She has only done two poos the last week. The first one I could tell she needed a poo and I sat her on the potty and waited with her. It was almost like she was scared to do it but I sat with her and encouraged her and she did a massive poo. Then she didn't go for a few days after that and ended up doing it in her knickers even though I was encouraging her to do it on the potty

Has anyone else been through something similar? I'm a bit worried as it feels as though she is leaving it for ages as she's so worried about doing it on the potty. I've also tried her on the toilet but she's exactly the same. Can anyone recommend anything I can do differently?
TIA

Put a nappy over the potty, or pad it out with loo roll, they don’t like the feeling of it falling away.

Reading with interest OP as my son is in a similar position! He is 2.5 years old and absolutely brilliant at doing his wees on the toilet. In fact, he's been doing so for about 2-3 months now.
But he's only ever done one poo on the toilet. He either soils his little boxers or he waits until he has a pull up on (before bed) to do his poo.

I have tried encouraging him with stickers and rewards but he's not too bothered! Really hoping that one day it'll just click!

My son was very motivated by a chocolate button reward after for a poo on the potty

Try not to worry. It’s only been a week. You could try bribery and explaining poo goes to poo land, I think there’s a video they can watch about that. I’d also make sure she’s drinking plenty and isn’t at all constipated, lots of fruit and veg etc. The last think you want is her withholding and it being painful when she does go.