
Madame Labrance is... OK and fits in certain decks, but I probably see a lot more people running her than I should do. Yes, obviously she works with Dark Horse, and if you're going to be running on empty, you can hopefully use her every turn, and she has some nice interaction with Lucky! here. So all that's good. But even then the opportunity cost in playing her is quite large, and you might be better running something else.
Firstly, how often will you play her in time to make a decent profit? Most of the time you will be using her for resources rather than cards; all the decks that build around her tend to do that, so lets focus on that. (We're doing her a tiny injustice here, as a card is slightly better than a resource, but not by much. If you assume x1.2, you need 5 card draws to count as an additional "resource" which almost never happens with her. There is probably a cardless Survivor archetype with this and Last Chance waiting to be discovered, but for now its not well served enough to build around, so resources it is). To be better than Emergency Cache, you have to reliably use her ability 6 times. With the average game lasting around 15 turns, that's not unfeasible, but there will be games where she arrives too late. She delivers her value slowly, and generally we prefer spike value to drip value. She also has a 2 resource hump, so sets you back a moderate amount. None of this is major, but often you can get to the end of the scenario, have used the Madame 5 times and think, "wow, that was great", but it really wasn't - it was poor. You need 10 uses to say "wow!" and that is quite rare. A lot of people love the 2/2 soak for 2, and sure it is quite good, but it's not hugely significant compared to other allies (and Survivors are quite well served for damage soak anyway).
And that brings us to the big problem, the big opportunity cost - the Ally slot. The Ally slot is the strongest slot in the game, and by demanding this slot off you for her drip-feed of loot, she is punishing you quite severely. You're missing Peter Sylvestre(0), Peter Sylvestre(2), Yaotl, Aquinnah(3), and thats before we get into cross-faction allies for Wendy, Yorick, Pete, Minh and others, not to mention the campaign allies in Dunwich/FA (or the to-be-proven On Your Own). Yes, there is Charisma, but now you're paying XP for a moderate drip-economy card when you could be buying Will to Survive instead.
Anyway, I don't want to hate on the Madame. Like I say, she's not bad. But most of the time when I see her, I just wish my friend was playing Peter Sylvestre(0) instead.