Does she use gmail as the contracts still should be in there?
Has anything like updates etc been actioned that could have caused the contacts issue ?
Do she use the Stock Contacts App to store her contacts ?
Current Phone ~
Samsung Note 20 Ultra 5G SM-9820 _256Gb SnapDragon 865+
Samsung One Ui 2.5/ Android 10.
There's an option within the settings to select which categories of contacts to display. Make sure that "All Contacts" is selected before you try anything more complex.