Am I wrong for leaving??

I work late morning shift- night ( 8 hours) and today I texted my boss to let her know in advance before my shift that I had to leave early to pick up my son from his dad. She replied that we’ll discuss leaving early when I get in. I proceed to come to work and she dosent mention it, I then go back to her office after getting started for the day and she’s now gone for the day. So I text her to remind her I have to leave and now 2 hours later ( 3 hours total since I’ve been at work) and she hasn’t replied. I’m already late picking him up , should I just leave or what would you do?