Can you add an account to someone else Tik tok app in the USA?

It’s gone from my phone because I had to factory reset it. Now my old phone with it on doesn’t want to turn on. My mom uses TikTok and I know that you could have multiple accounts as I have another one, but because of this weird thing,

I’m wondering if I were to try to add another account to her app, will it get fucked up in a way Where she ends up not have access to her account?has anyone done this? Also I’m in Italy right now.