Laurie's opinion on gay marriage
Laurie's opinion on gay marriage was an opinion on empty ceremonies, as, at the time, there was no place in the US where gay people could legally marry, and it didn't even seem to be on the horizon.
But Laurie is clearly a person interested in commitment and stability, as well as creating a good home environment for her daughter.
How many people think that she would have been willing to marry Ellen (or someone) if it meant something-- that is, if we fast-forward to legal gay marriage in California, and Ellen and Laurie are still together, with all the compatibility and commitment that implies, would she marry Ellen then?
I didn't hear her objection as "We're different, and don't need heterosexuals, or outside validation." I heard it as conditional: "a ceremony wouldn't mean anything," with an unspoken "but if it did...."
A lot of Laurie's gestures are very conventional-- roses on the table, candles in the bedroom. She may be into bending the dominant paradigm, or even subverting it, but not tossing it away entirely. She wants Edith Piaf, not Cris Williamson, or Alix Dobkin (two women who put out early, ground-breaking albums of lesbian music).
So I think that when California allowed gay marriage, Ellen and Laurie would have happily shown up at city hall.