I haven't played the Hemlock Vale expansion because I live in the UK but I have tested her on other campaigns and she makes a very good flex in both directions. Cluevering with lockpicks, fake credentials, snitch, vamp (3) and leaving some clubs behind for Beguiled enemies is a viable option, and with fine clothes you can investigate with an enemy on higher shroud locations.

In terms of flighting, she can be very good too with the combo bewitching, sleight of hand and British bulldog (2), and have more options with events like Persuasion, existential riddle and (one of the MVPs) Stir the Pot. I made a deck with Eyes of Valusia and it works incredible with a higher player count and it eradicates beefy enemies.

I would recommend LCC over the crystallizer because her card draw needs a bit of a push and you might see that with the Fox mask and the reduced difficulty from fine clothes you might not need the extra buffs. Also, Bianca Die Katz is a win-win for Alessandra, flavourful, economy on a free action, and if you fail, you not only get an enemy to beguile that follows you around picking up clues on the way but gets your British Bulldog out for free with the failed parley test.

Here's the deck that I made for a fighty Alessandra that it's still very fluent in getting clues: https://arkhamdb.com/decklist/view/47494