Whether she was a looky lou or a potential client, she should have called you to let you know she wasn't taking the spot.
Honestly, I don't like being lied to and I would be pissed off at that. If another provider wanted to see my space I would be happy to show her, but disrespecting me and her other client by lying shows me I wouldn't want her as a colleague, friend nor would I send my child to her for care.
Either way, she showed her true character.