Thanks for all the great information folks! I've got a larger scrim I'll bring along, I pretty much expected to be going for as much soft light as possible. I've since contacted the model and she will be bringing along several props she can use during the shoot. I do really appreciate the advice differentiating between a lingerie shoot and a boudoir shoot, it's given me some great ideas with a few of the clothing items she'll be wearing.
As for the female assistant, the model has her own MUA that she is bringing along (a close friend of hers). I'll ask her to adjust or keep an eye out for things, but it tends to be the case that I'm the one making adjustments, and I just don't see that changing here. I've never had a model be uncomfortable with it in the past, but who knows, it could change here.
I'll make a post when the shoot is done, though I'm not sure where, since the NSFW photos are limited to supporting members only.