Should I tell my therapist that our kids are taking classes at the same place?

Not the same class. My kid takes guitar lessons at 5 and the other kid takes piano at 5:30. It is not for sure they would figure it out so maybe it's not necessary? I am usually driving a different kid to their activity that day and would rarely be there again, and also we see each other on Zoom so maybe they wouldn't place me if they see me across the waiting room. Also it's a big narrow L-shaped waiting room so it's also not for sure they'd even notice me there. What's the etiquette?