G Mail Account

My Sister has a Galaxy A20 SmartPhone.

It was going so slow and just not working Right.

So She somebody in a Service Place did a Factory Reset on Her Phone.

But She Forgot Her G Mail and Password so they Made a New G Mail Account for Her so they could get Her Phone Working.

So everything is working good and She has all of Her Apps and everything.

I Told Her I have Her G Mail Account and Password for Her.

Can I just Sync Her Phone to Her Old G Mail Account and Delete the G Mail Account...

G Mail Account