D.B.
Honestly, I would give them a card of support, and do a collection that puts money right into legitimate relief efforts in Paris. Here's a place to start:
http://mashable.com/2015/11/14/paris-attacks-how-to-help/...
You want to be sure you are dealing with legitimate charities though, so research! Charity Navigator is a good place as well. A lot of scams show up at times like this. We saw it in my area after the Boston Marathon bombing.
You could start with the class, but you could turn it into a community outreach project as well.
I'm not a big believer in flowers for something like this. I don't do them for funerals either. They die, they accomplish little. Wine and French gifts? Wine is transitory, gifts are short term comfort. If their hearts and heads are with family, friends, and Paris in general, then put your efforts to work there.
I wish the people in Beirut and Kenya and Iraq and Syria had people like you who want to do something for them. These bombings didn't even make half of the news broadcasts, and no one is putting "prayers for Beirut" on their Facebook pages. So if you do something community-wide, you might consider making it beyond just France, but for bombing/terror victims of all colors and religions. Doctors Without Borders (Medicins Sans Fronteres) is one worthy organization.
I hope your teacher friend gets info on family and friends soon.