Could she be coming into season? That can affect behaviour (sorry, I don't know if she's spayed or not). Otherwise, no idea, but if her initial anxiety made you feel embarrassed she may have picked up on that and become more anxious.
One of my two is nervous of strangers and barks and isn't sure whether to hide or approach, so I take the pressure off him by initially putting him behind a baby gate and telling visitors to completely ignore him. He can see the visitors but can also hide from them if he wants to. When he relaxes I remove the baby gate so he has the choice of approaching the visitors or not. I still ask the visitors to ignore him. It helps his confidence.
Hopefully you won't have to do that with Mae and she'll be fine when you have visitors in the future. But I think next time you're expecting visitors it wouldn't hurt to have a plan in place to help her find her comfort zone and to give her the chance to keep her distance if that's her choice. Leave it up to her to decide if she wants to meet them