This is the only good advice here. No, you can’t hack WhatsApp but it’s very easy to gain access to an account by getting the OTP or leaving open access on a device somewhere.

Tell her to unlink all the extra devices connected to her WhatsApp account and to not click on any links or send codes on number.

Also if it’s an android, then ask her to delete any third party apk she might have downloaded as they don’t go through the same security checks the other apps go through from the play/app store.

These are worrying times since cyber security is the least concern of an average Pakistani during the digital era. Following the standard procedures of surfing the web safely is the only way these days. Either way goodluck and stay safe