The answer hinges on the expectations that the company has from you.
If you and/or your work somehow slipped through the cracks and you know this but you're keeping quiet and staying low while there's actual work to be done - stop and find the most tactful way to start doing some actual work.
On the other hand, if the company is aware of how little work you're doing and they're happy to keep you on[1], in that case you can look for extra projects at work (they don't need to fill all of your time), spend time learning things you're interested in (related to work or not) and spend time with your kids completely guilt-free.
If you're early in your career, at some point it might make sense to leave and go somewhere where you'll learn more from actual work.
[1] Yes, this really happens. Maybe they expect future projects, or still building the team, or there are some org changes coming up, or they care about appearances and want to be able to say that they have a data scientist on a given team.