"working from her computer"
Wherever the employee physically located while doing the work creates nexus for the employer in the location the employee is in. For the employer, hopefully they are already "in" the state(s) the employee is working from, instead of this employee creating a new state nexus (don;t ignore the locality nexus issues, such as different min wages, local taxes, PFML, etc.). Hopefully the employer has complied with their requirements, such as treating the home location as a proper "office", such as labor law posters, liability insurance, etc. The employee should mostly care about the liability insurance aspect.