("No!"...? I don't know what that's all about.)
It depends, apparently.
If she was eligible to be on your original application for Residence, but was not included at the time, then see here
http://onlineservices.immigration.go...nual/46515.htm and here.
http://onlineservices.immigration.go...nual/30541.htm
If she was not eligible before, the partnership regulations don't seem to make any requirement about English. Here are the rules - you can look through for yourself.
http://onlineservices.immigration.go...nual/30875.htm