Hello
I hope this is the right place to post this question. Otherwise, let me know. 
My mother was born in Taiwan and lived there until she was 19.
She later moved to Europe, got double nationality, and stayed there during the last 40 years, visiting her Taiwan relatives every 1-3 years.
Because she didn’t need her ROC ID anymore, and was using her other nationality ID card most of the time, her ROC ID got expired years ago, and she didn’t ask for a new one. She just kept her ROC passport somewhere and used it from time to time.
I am currently a ‘ROC National without household registration’ (two passports, one foreign ID), living in Taipei and looking forward to getting a Residence Permit (居留證) and maybe an ID. So, aside from other documents, I need my mother to come to Taiwan and renew her ID (it’s one of the requirements for my 居留證).
My question is:
How long does my mother need to stay in Taiwan to apply for a new ID and receive it? Some people said a few days. Others said 6 months.
Hopefully somebody knows the exact answer.
My mum did not “lose her ID on the street and is getting a new one”, the last one she had expired years ago and she didn’t renew it, so it’s probably a different situation.
Thanks!