The Lifetime Learning Tax Credit $2,000 says "per return." If my wife and I both have college tuition expenses (2k and 4k), should we file separately?

We both have 1098-T's

Mine is for just over $4,000, hers is for over $2,000.  

I'm wondering if we filed separately, could we both get the deduction for $2,000?   Right now, only she is.  Is that because we are filing jointly and we have only one return?