35 month old scared of using potty - wees and poos

[Corky]

I have a friend who's dd is having a real battle with trying to get her dd to use the potty. She is very keen to wear pants, but after one wee on the potty at bath time she was so traumatised that she won't wee at all on the potty and holds it in for 8 hours or so - with no accidents.
She is not sure whether to persist as there are no accidents but she gets very upset when she really needs to go.
She will sit quite happily on the potty with my own dd but will not wee.
My friend has tried sticker charts, biscuits, sparkles in the potty and even lining the potty with a nappy all to no avail.
Any ideas or should she abandon the idea and try again later.

Maybe she would be happier going straight to the toilet rather than using a potty. Otherwise I'd say abandon the idea and try again when she's showing interest.

She will sit on the toilet with a trainer seat but still doesn't wee. She does also ask to sit on the potty when she needs to go, but gets scared last minute.

In which case I think it would be wise to take the pressure off her and put her back into nappies for a while. They need to be emotionally ready as well as physically, and it sounds to me as if she's not emotionally ready yet.