Emmanuelle grew up speaking French, according to IMDb.learning in this thread that Emmanuelle Vaugier speaks French puts that in so much more context for me, though, also knowing she's Canadian. I mean, obviously I don't know where and how she learned her French exactly, but I speak it too -- and while that's not only from school, almost ten years straight of mandatory French classes didn't exactly hurt. :lol:
A lot of people in the US speak Spanish, yeah - nationally, there's no 'official' language, but Spanish is the second most commonly spoken language here. Plenty of us don't know enough to say hello or goodbye, but a lot of people do know at least a bit. Ultimately, it really depends on where the person lives and where they go to school that would dictate whether they're likely to have a working knowledge of the language - I'd expect the number to be especially high in a major city or somewhere with a large Spanish-speaking population (like NYC). Two of the characters having some knowledge of the language is certainly within the realm of possibility.
I tend to give more leeway where Jo in concerned at this point since the character is new. Her going to Spain for the FBI several years ago makes sense since we know so little about her - a bit convenient for the plot, of course, but then this is CSI:NY. Personally, my main beef with the Lindsay portion of it in this episode was the context and the delivery. Learning Spanish (or teaching your kid to speak it) is never a bad thing, but to me the whole thing just seemed to be shoehorned into the episode as a way to say 'Danny and Lindsay are married and have a kid, remember? And Lindsay is clever!'