Thanks, everyone.
We've kept them apart for a week in separate rooms, and so this was the result of letting them sniff the air for a bit -- so far so good -- except Pansy has dried lick marks all over her head now, lol.
Ruby is scruffy -- reminds me a bit of Benji! I'm glad other's cats/dogs are getting along -- I had a feeling that Ruby would be overjoyed.
We've been working since we got her to do a down-stay whenever she sees a cat. She'll just sit there and look, and so will the cat!! It's come in very handy with Pansy -- and they both love to play, too. I've just let them work it out and so far, they've both set their boundaries and are now in the process of finding the most comfy position to nap together on the couch, bed and floor.
eta: I think it also helps a bit that they're both babies -- Ruby is 8 months and Pansy is 12 weeks. Hard to tell in the pics, but Pansy is a kitten (Ruby is around 12 pounds).