I think you'll have to resign yourself to taking the potty with you for much longer, as I think you're rushing DD into using the toilet. Be happy that she has trained so young and at her own instigation! If you force the issue, you are asking for trouble, the more you push the more she will resist.
Would she use something like a potette plus for trips out, so that eventually she could use it in toilet seat mode, and it would still feel like the potty that she is used to? Something familiar like this would help the transition as you say she is wary of change. It would also fold smaller than an ordinary potty for you to take out and about.
I would wait until DD is entirely confident with the potty before getting her to sit on the toilet. You could start preparations for this by letting her choose a comfy seat for it, and have practice sessions just sitting on it, to get the feel of what it's like. Make it clear that it is just sitting, that she doesn't have to do anything (choose a time when she doesn't need to go, she could keep her pants on if it makes her feel any happier)You could offer a bribe if you want, make sure you stay with her as she may be scared of falling off or being flushed away. Progress to sitting without pants on. If she gets off and uses the potty instead, don't get cross. One day she will probably decide that the toilet isn't scary after all, and use it, much as she did with the potty.
The key is to let her do this at her own pace, and provide the means to make it easier for you all, two weeks is nothing in the grand scheme of potty training, think three months at least of taking potties, and much longer for changes of clothes in case of accidents from now.