I had exactly the same situation. My supervisor has 2 students (including me) and in the 4 years she was in the department (she joined the same time as me) she didn't publish a single paper with either of us.
Initially I tried to be very involved, deliberately going to see her at least twice a week to discuss things, going through my workings, asking for advice on what literature to read etc. I realised within 3 months she wasn't really engaging in anything and her other student said the same to me. The supervisor published 2 papers in her first year there, both jointly with people she knew from other universities. As I became more involved in collaborating with them I realised she didn't actually contribute anything to the work beyond the most superficial (largely thanks to how her English was better than the collaborators so she always did the writing up...). In one instance she presented "her research" to the group in one of our weekly internal presentations and at the end I leant over to her other student and whispered "Every single result in that presentation [Collaborator 1] sent me 3 months ago, she didn't do any of that!".
To make matters worse she was away the entirity of my 2nd year due to having a child (and when she returned she'd mentally 'checked out'). I felt completely lost and without direction, due to the fact all the other people in my domain were elsewhere in Europe or in the US. Eventually I managed to give myself some drive in the area AND I picked up a 2nd supervisor on a different topic. By the end of my PhD I'd published a paper with the 2nd supervisor, one with the collaborator and one entirely on my own, without her even reading it. I'm also certain she didn't read my draft thesis. She didn't read any of my paper drafts. I once asked her "Have you seen anyone do this sort of approach before" and she said "No", only for the External Examiner of my thesis, whom she picked, to say "I did a similar approach in my last paper". To find that out during a viva was a hell of a shock! I managed to defend my thesis though, my approach and ideas were different but I'd definitely have benefited if she'd informed me correctly.
Her other student wasn't so lucky. Our supervisor actively blocked her taking up a 2nd supervisor. She'd also done enough with the student that the student couldn't publish the work herself without breaking rules. The supervisor sat on a final draft of the student's paper for 9 months! Eventually the other student had to take her to the Head of Department to force her to either sign off on it or fully bin it because the student was approaching the 4 year deadline.
We both managed to get our PhDs and I think I came out of it stronger but it's not something I'd like to repeat. I couldn't say "**** you to Dr [Supervisor] for being useless" in my thesis but all I did was acknowledge her existence. I didn't mention her in any of my papers at all, which might be considered the height of rudeness usually but that was kinda the point... I think the department realised it was something problematic too because she didn't publish another paper and ended up leaving Academia 6 months after I finished.
In terms of ways of dealing with it I found that picking up a 2nd supervisor really helped. Collaborating by email is okay but it doesn't replace a face-to-face discussion in front of a blackboard. Ideally it's in an area with a lot of overlap with your own, it'll make it easier to hit the ground running. By making progress with this second strand of work it reduces the stress of working on your original problem and often that's enough for you to start making headway on your own.
You definitely need to be regimented with your time (though you could say this about doing a PhD in general). With no one looking over your shoulder it can be easy to just become apathetic. Keeping a schedule and daily routine helps to avoid that. If you're stuck on something then don't just stay at home that day, find a paper in your area and try to rederive the results (I was in theoretical physics so lots of maths workings) or work through the details the paper might have glossed over. That way you're keeping the subject active in your mind and who knows, maybe you'll think "Hey, I can do this a much better way!" and there's the spark of a paper all of your own.
At the very least, talk to people. Don't shut yourself off from other PhD students in your group, either socially or professionally. The occasional rant or indepth discussion about some aspect of research can be mentally uplifting.