Will not wee out of the house

[Goblinlamp]

DD is 3 and at home has been toilet trained for two months, literally no issues at all. At nursery and when we're out and about she just will not wee on the loo or travel potty and holds it until she bursts. She'll sit on it, do nothing, then either keep holding or wet herself. She tells us she's never going to do it and will just keeping doing it either in the house or in her trousers. We are going on holiday in a couple of weeks and I've no idea what we're going to do, really not wanting to use nappies again. Will she ever be able to do it?! How can we help?? This feels like the hardest bit of parenting so far!!!

Potty training is really really hard. you have my deepest sympathy. We had a lot of poo issues when. Potty training and the best thing that worked for us was bribes. Everytime he did a poo he got a treat. He clicked on pretty quickly.

I think you have a couple of options 1. bribery 2. go back to nappies.
I had the opposite issue when DS was three. He was dry outside the house and wet himself in the home. After 6 months and numerous different approaches one day after coming come from a day out and Ds staying just in the hall and wetting himself I said the following:
Ds you know when you need a wee but you are choosing not to use the potty/toilet inside the house. But that’s what babies do and babies wear nappies and thats totally ok to be a baby. So you are going to wear nappies again.
Within 2 days he was dry in the house again and out of nappies. Just did it himself.
I realised it was a control/attention thing
Maybe worth going up to pull ups while you are out and about. Eventually she will be ready or will ask to use the toilet when out.

Or pull ups. Good half way House. Another option might be reusable nappies/pull ups. As they feel the wetness more. But that could backfire.