Stay away from co-leading
If you deserve to be promoted but for whatever reason your superiors don't want to formally promote you, you're in for a co-leadership.
Pay attention who is your co-leader: if it's a man, then that man will someday become your boss. If it's a woman, you're probably both seen as difficult and got not only the same reward, but also the "chance" to tame yourselves while producing probably 4-times the results expected from literally anyone else.
Co-leadership is tricky:
either one of the two can have meetings that exclude the other one
one of the two will be preffered by the superiors
everyone you're co-leading gets the messages of who's included and who isn't, who is liked and who isn't
two leaders create confusion with clients, who don't know whom to address when. This results in either client running away or in them picking sides too.
Let me tell you my story: I co-lead a small team with my male colleague. While he is a very nice person and a professional I respect, and while we talk openly about "our situation", he has a (good) history to higher management, he is younger and he is geographically closer to the higher management. I know he has dreams of being "able to implement agile as it should be done" and that he expects rewards for the hard work he's been doing the last years.
Last year, as I was assigned to a complex project with a tight deadline, he led some activities of our small team. Towards the end of the year, he took sick leave for a month, during which I took over our small team. Now he's back, and although he's assigned to a project himself - while I finished my project - he insists on managing the team and the pipeline and the activities on his own.
I offered to take over workload more than once, but he still sets meetings where he is alone, and expects me to invite him to all meetings where stakeholders invite only me. The team members don't know who is doing what, and clients are equally confused. This morning, he forwarded me information from the broader organization, where he was listed as the only leader of the team.
So I reacted. I wrote to our superior, CCing my colleague, thanking my colleague for forwarding the information and asking my superior to inform everyone if my duties have or haven't changed. The superior informed only the colleague who didn't know that we were co-leading, and the whole event left me equally angry and embarassed.
I wonder now how many times I'll have to make that point, I wonder how crazed and power-thristy will I look if this is a point I make repeatedly (and I know I will have to make it repeatedly) and isn't that futile anyway? I will never get access to the same information as my colleague does, I hate hearing "he was there" and we both lose so much - even in human, reciprocal respect - by being into this absolutely fake competition.
There is no working co-leading and every woman should stay clear of that concept. For women, it is likely more dangerous than for men - though I still have to see a man willing to co-lead with another man.