AIBU to want to tell colleague that she is being manipulative

[Disastermagnet27]

I have a new colleague at work and ever since she started she has been very vocal about not liking the way myself and another colleague do things. She only works part time with my other colleague. I work full time.

The new person (I'll call her L for ease) and I are similar ages and my other colleague (R) is quite a bit younger.
R works 3 days and L works 2. R has just come back from maternity leave also which is relevant to the extent that R is trying to cope with working again with a young child.
L has basically had a tantrum about the way we work and I think doesn't want to work with me as she doesn't want to share any of the work she does. Right from the beginning, she made R feel bad about the way she worked. She complained over and over about the way we worked until R decided to change what we do which she was unhappy about but it made it easier to deal with L. I think R felt overwhelmed and that L used that and the fact that she is older and more experienced to get her own way. I really don't like that trait in people.

It has also had an impact on me, meaning I'll have to work more on my own which is not really how my job works most of the time.

To be honest, I'm not that bothered for me but I am annoyed for R as she instigated the way we work and it did work very well for us and for others involved in our job. I feel that L has come in and decided she doesn't want to do it as it is more work at the moment but in the long run it won't be.

I think she has been nasty and manipulative and played on R's insecurities.

WIBU to tell her that I don't like the way she's behaved and that we are working in the way we always have and she'll have to put up with it!?

I think you need to assert a sense of authority over it or go to your manager.
I’m all for a fresh set of eyes making suggestions but if it’s becoming disruptive then that can’t fly.
If it really isn’t working out, I’m sure L will be under some sort of probationary period.

This is one for your manager.

But first, is anything she is suggesting actually a good idea?? Once you’ve thought, go see manager, explain the issues briefly - find agree a plan eg that you will talk to new colleague and say you need to do XY to fit in w your system but yes we’ll try doing Z your way (if any of her ideas are any good). Hopefully that will sort it - if not the 3 of you will need to meet with manager, and they can take it from there.

‘Only’ part time

As these are peers and you’re not the line manager, stay out of L&R’s business and seek to resolve your differences about ways of working with L, or if this proves difficult, involve your manager.

There is nothing wrong with a new person suggesting new ways of doing things. Sometimes it takes a fresh pair of eyes to see opportunities for improvement. Your post is quite emotional so it is hard to cut through that and actually see if the new person is actually making sense or not.

It depends what it is, can you be more specific?! But really as others have said, your manager should make the call.