You need to explain to your mother, that although Hijab is Fardh(compulsory), there are many other ways in how you can wear the Hijab, which helps preserve modesty, e.g. through your actions, behaviour and the way you dress.
The hijab shouldn’t be forced upon you.
If you don’t want to wear it, then don’t. If you do intend on taking it off, do research beforehand on the hijab and it’s importance and maybe that will increase your understanding and respect for it.
- there’s not much to tell your mum either, just take the cloth off your head and tell her, I’m not ready for it.