Unfortunately, accounts cannot be recovered once deleted. The Help Center has an article on account deletion that says this explicitly, which you can see here: https://support.khanacademy.org/hc/en-us/articles/360034662972-How-do-I-delete-my-account#:~:text=Note%3A%20Deleting%20your%20account%20is%20a%20permanent%20action%20that%20will%20delete%20all%20progress%20and%20put%20a%20lock%20on%20your%20username.%20Your%20account%20cannot%20be%20restored%20once%20deleted. 

It normally asks 2nd time to conform so everyone should probably be careful when you get 2ND ALERT and you cant recover your account

How did she accidentally delete her account if she had to go through all three steps of removing it?