This is a huge development in the curly dog household!
Indy is very... individualized when playing with toys. She will chase after a thrown toy but she won't bring it back to you - she'll go to another spot to chew/squeak it. When I'm playing a game of tug with Lucky or if Lucky is fetching a toy, she'll bust in, grab the toy and tug it away from him and then run away - and it's not to solicit a game of chase.
Lucky tries to solicit games of tug from her, the same way he teaches little puppies, but she doesn't understand what he's doing. So he's very confused and stressed when she yanks the toy away from him and goes off by herself. And also I think he remembers her resource guarding from when we first brought her home, so he doesn't pursue her to try and force the issue.
They play wrassle and chase together but if you add a toy into the mix it's not playing for Indy - it's competition. And she's determined to win. It's never sat well with me that Indy refused to engage in normal canine social play. It is a rather large red flag. Ironically, Patricia McConnell recently wrote a very similar post on this topic between her two dogs, Will and Hope, with much the same set of worries. Because Lucky is such a rock-solid dog in terms of temperament, unlike Will, I've never worried it would become a source of serious conflict but it IS a source of stress for Lucky, which I think has manifested itself in a few episodes over the past year (one this past July and one in April). That's a problem.
Well, last night Indy was squeaking on her new dead fox toy and Lucky was clearly in the mood to play with her. She was receptive to the idea of a good round of wrassling but also really wanted to play with her fox toy. After a few false starts where she would squeak the toy and then go dive at Lucky to jaw with him, then run back to squeak the toy, she carried the fox over and dangled it in front of him. Lucky was hesitant at first but after a few test attempts at grabbing the other end, he grabbed the fox and they began to play tug.
I was so excited I cheered and started clapping. Which made Indy stop and look at me. Lucky gave his head a little toss, making the fox shake, and she grabbed at it again and they tugged a bit more. I toned down and started quietly saying "Goooooood girl!" while she kept playing. It didn't last long because they switched to chase zoomies (sans toy) but it was there - she solicited the interaction and treated it as a game, not some attempt at pulling rank.
It's taken a year to get to this point. I don't think we're thru the woods by any stretch, but this is very encouraging.