Arc, it was her round about way to asking the other lady to get off the phone or have a conversation somewhere else.
Maybe a "No phone conversations" sign in the waiting room might be something to bring up to management. Texting ok. I know ours ask us to turn it off or turn off the sound so it doesn't ring.
Someone who is respectful would've had their conversation in the hall.
Nice you have options for them to wait in.