Can I represent my mother. I have a signed form t1013. do I have to mail it to CRA first or can turbotax expedite?

You'll need to file the T1013 with the CRA directly. TurboTax doesn't support the T1013.

If your mom is set up with a CRA My Account, she can sign in to her account and grant you authorization, so you don't have to mail in the form.