A rep for the mom-to-be declined to comment to PEOPLE.
The news came just days before big sister Kate Middleton had her baby.
A source previously told PEOPLE that Middleton and Matthews are looking forward to settling down and “having children and leading a quiet life.”
The charge reportedly relates to an incident that allegedly took place between 1998 and 1999 in France. A complaint was made about the alleged attack in 2017.