Who cares what she is spending time on.. Enjoy your kids. If she starts doing it consistently then it will become a problem.. But for now I would say try and get as much time as you can with them and enjoy every second of it.
This^^^^^^^^
Take the kids every chance you get. Keep track of it in your parenting "Log book".
Somewhere in the future, you can look back at the logs and decide if you want to address this as an issue.
"What is best for my kids is best for me" Amor Fati Link to quotes: https://www.divorcebusting.com/forums/ubbthreads.php?ubb=showflat&Number=2879712