Well, it certainly wouldn't do any worse than lying to her and keeping secrets.
Yeah, she doing a bang-up job, getting drunk and leaving the door unlocked, mother of the year.
Either way, I am not going to change your opinion, and you are not going to change mine, so there is no point going round and round.
Yeah for sure Charlotte isn't handling everything perfect, i'll give you that point.
But after all, there is a Story to tell and also this Story has to continue.
I think there was from the Storytelling no much space to improve it, if Charlie had told Emma right in the beginning smth like:
"Sweetheart this is (insert MCs given name), i have hired him for you as Bodyguard, bc you are being stalked and i am worried."
I think then it would be harder (from the Storytelling) to gain more trust from MissC, bc actually "we" have to keep it as secret.
So also (but this is just a wild shot from me in the blue), Emma IS suspeccting that there is more going around, than she was told, and _maybe_ she would do something "stupid" like trying to investigate what is happening and it would lead in a dangerous Situation "we" have to deal it. (I have still the picture from the quit window in my mind).
So this could be some options into the Emma route (rescuing her/she sees "us" as Hero/Love Interest) and also as example on the Charlie Route (rescuing Emma -> more trust/beginning feelings towards the MC).
So (still my guessing) then "we" can have a serious talk with Charlie about the drinking, and also if we have earned enough trust, telling Emma what is exactly going on and that she is in danger and as long as the situation isn't handled.