@tukker - what bac is your DD going to do ?
Bac S is mainly geared towards maths/sciences/geometry/numbers etc. They still do languages and philosophy but the grades she'd get in these subjects would count less overall in the final bac grade (I.e in a bac S, the grade given in philosophy counts times 1x but the grade obtained in chemistry for example counts more, for example times 4x). This is well suited to someone who's interested in studying medicine at University afterwards, or engineering etc.
Bac L is all French literature of course... Voltaire, Flaubert etc etc. Philosophy of course. And foreign languages. Like PP said, she won't be learning how to conjugate French here but will be fully expected to have read all of the old French classics, expected to be able to write long essays articulating beautifully and referencing her opinions. It's seen as a more 'artsy' bac, think book worm, art gallery, novelist, poetry, journalism etc.
Bac ES is sociologie, economics, leaning more towards business, current affaires/geo politics and of course, foreign languages and philosophy.
These three bacs are called 'un baccalauréat général' and are very well regarded. Mainly because it allows you to study the general university degrees (licence/master).
There is also the option of doing one of the bac technologique - brought into help those seen as less 'academic' and more 'practical' - studying computers/technology, business, management, HR, négociations, some basic law and economics. And foreign languages of course. And so much more!
However with a bac technologique, your DD wouldn't be able to apply directly for a bachelors degree for example (une licence). She would have to take a different route into university via a BTS/DUT which is a two year university course - more practical/less academic.
I would strongly recommend that your DD redouble into Second where she has time to find her feet and get to grips with the options. All kids in Second are sussing out which bac is best suited to them, and they have until the end of the year to choose their bac option. The ones strong in maths will choose S and the ones good with books usually choose L. Those who love human sciences may choose ES. Those who love technology, business development/strategies or management might choose from one of the bac technologique... the point is, in second you can do a bit of everything , see what you're good at and then choose your bac. Once you've picked, schools don't let you swap usually so it's important to get it right in second. If she goes straight into premiere and picked the wrong option, it could get messy for her.