Return to work after mat leave - maternity cover situation

[Stillnotautumn]

What have people's experience been with their maternity cover once they return to work? How long does the maternity cover continue to stay on in your role to "share" it with you once you have returned?
I had agreed with manager that I would use my KIT days to transition back in, and once I return I will be full time in my role again. However in my return to work discussion with my manager recently she said she wants to extend my maternity cover's role too get her to stay longer. When I asked her why, my manager said it is to support me as I transition back in. My manager mentioned that the cover will be joining my team meetings alongside me to support me. This will be after scheduled handover sessions with her so even weirder that she continues to support me in a role I am fully capable of.

I wasn't expecting the maternity cover to stay on when I came back and this is making me quite uncomfortable, especially as I have done my role for a while so I know it really well and don't need support. I work at a mid senior level and manage a team and I always got really great performance reviews before I went on leave.

Is it typical for maternity covers to continue to stay on and do your job even after handover and full time return? Am I being unreasonable in being uncomfortable that I wasn't asked if I needed support but instead "support" is being pushed on me? Or does it all seem a bit odd?

(Also wanted to mention that it is widely accepted by people who know her that my manager lacks empathy and emotional intelligence, so might provide some background.)

Thanks in advance for any experience with this that anyone can share!

First mat leave my cover was two people and upon my return the one went back to their original role immediately whilst the other remained as my assistant (as it was finally accepted I was doing the role of two people). When my assistant left the business it meant there was a designated role for them to recruit for, so it was actually handy the person had stayed on for a few months after I returned to balance the workload and prove the need.

Second mat leave, there was no extra cover. I had two assistants by this point and they were expected to pick up my work which was fine except for when one of them took annual leave, meaning the one would pick up the other's work and I was drafted back in to cover my own work (no more than a week at a time). I had expressed concerns multiple times beforehand about the lack of cover for team holidays but the response was 'AnnoyinglyOptimistic used to cover all of this work herself so two people can manage in her absence, and one can when the other is off'. That was ignoring the fact I was regularly doing 10-15 hours a week unpaid overtime during the period I was solo, and was leaving 20+ days annual leave unused at the end of the year 😂

What I found more to be the case second time around going back was that I relied more heavily on the handover process and took more time to get back into the swing of things, I subsequently lost one assistant due to team restructure although they are available on an ad hoc basis to cover some of the work during team holidays. Fortunately my remaining assistant is THE BEST and since returning we have definitely shared the workload in a different way which has been beneficial for us both.

I had a nightmare. I too did not need the crossover support. She was supposed to exit after one two-hour handover meeting and the completion of a piece of work which was basically one day. I ran three departments/functions. She (the maternity cover) went over the heads of me and my boss to the CFO to ask for more contracting work. I was forced to ask for her security pass back when she had not surrendered it (by mistake, she said, on the morning of day two, immediately before she then went and had the CFO meeting). So I got security to switch off her access.