Don't suppose the one that has the closest build to Sar'ai is drow or very dark skinned, eh? Or even elf for that matter?
Brandon, it might be best to use the bandit outfits to get close and then just take the guard out. With very few women in the bandit camp he should realize that we aren't bandits as soon as we begin talking. Lia is obviously much smaller than the women bandits were and Sar'ai's drow heritage will give her away. What do you think?
You do have other healers working with you at this time. You guys put in a good chunk of your own healing efforts, so I'll say the rest was handled by some of the other clerics and paladins hanging about, and everyone is back to full health.
P.S. You already used your Healer's Kit on Geoffroy, he cannot benefit from one again until he takes a short or long rest.
Edited: daishain on 16th Jan, 2017 - 2:18pm
Ok, sorry just now getting to post, but as far as Sar'ai and Lia, my plan was this: They will each dress in the garb of the female bandits, however Sar'ai will wrap her head with some bloody cloth to make it appear that she was grievously injured during the fray that just occurred to better hide her drow skin. Lia will be "Escorting" Sar'ai back to the northern camp and once there, well, we will see what happens, but Sar'ai has no qualms about killing the lone guard if only to keep him quiet.