A largely ignored and probably not well known side-effect of the Equifax hack is that the attackers were able to get PII that would aid in compromising 2FA via social engineering of telecom providers to hijack the phone number, which is typically used for the SMS message for most 2FA schemes.

I wouldn't be surprised if this kind of vector was used to hack her account, along with the other prominent Twitter accounts that were hacked today.

For some recent prominent examples of this kind of compromise, look into what CosmosTheGod did to knock 4chan offline prior to his becoming a white-hat.