From the Sonic Legacy comic there's Tempest the Dolphin. Who's a kindred spirit of adventure like sonic himself. She's a fast swimmer, she can cook. And possibly help with Sonic's aquaphobia. Plus, since Tempest loves experiencing new cuisines. And Sonic travels across Mobius and different dimensions. The result, one diverse couple.
And then there's Nicole the Holo-Lynx, she comes from the Sonic Archie comics. Sure she doesn't have an organic body. But due to her history with the true blue. How he played an important role in Nicole's development. And with their universe being altered by Eggy, they would make a very supportive. And caring pair.