Short story is I've worked at the same place in the same job for over 20 years, the job is fairly mundane but it's local and fairly good money.
A colleague on a higher grade with a specialised role has sadly recently gone off on what potentially could be very long term sick - may not even return at all. No one really knows what he does as he never shared it with anyone but it is a very necessary part of the company.
Another colleague on the same role and grade as me (who's only been in the company two years and who is determined to get on and step on whoever to get there) has muscled in and taken it upon herself to try and pick up his job despite me offering assistance to our manager. She has managed to make the job hers and is not prepared to share any of the knowledge with me or let me assist in any way. Manager doesn't really care as long as someone is doing it but I would like to understand the role in case the sick colleague doesn't return and his job becomes available.
Team leader in between us and manager finds it all a difficult situation and isn't strong enough to manage the situation and share the work between us. Today, meetings have been arranged by team leader and colleague to work out the elements of the role and how to carry out the extra job. I did tell her I was disappointed that I hadn't been included but she didn't really say much - I think she feels unable to deal with the situation.
Any advice? Should I just suck it up or demand to be included? It sounds so childish of me but I'm sick of this colleague muscling in and making this empire for herself to get on at the expense of others who are keen to develop too.