One of the short comings of using Trisquel is the lack of non-free support
and the parroting of that fact. Word of advice... don't mention it's
non-free. ;)
What's the exact make and model of the wireless card? Is it integrated?
Obviously, you know that what you specified is the chipset for that NIC.
I ask because one of the great things about the GNU World is that while one
project maybe non-free there may or may not be other Free projects for the
same thing; i.e. project forking or driver compiling. Warning, a lot of times
the drivers are experimental. But, you can help the community by using it and
reporting bugs to the project developers.
Another possibility is that if you were able to get it to work on a previous
version of Trisquel then you should be able to get it to work if you updated.
You just have to use the software in the old repos. This way people can't
bark at you for using non-free software. It came from the Trisquel repo...
you're just using backdated/outdated software on purpose.