I'm back.
To answer some questions and clear up some speculation;
I am definitely, definitely not jealous, feeling 'sour grapes' or bothered in the slightest that she's on this secondment. It is not a job I'd ever ever want.
@Unicorn2022 Changing the lunch times isn't an option. To clarify I work 8pm until 7 am. The 'lunch' I get now is at midnight. We can't change it because at the moment there are only us two working and a third colleague who isn't on our shift comes in to cover from midnight until 2.
@KettrickenSmiled as to why keeping it to myself, well because I don't want animosity when there's just me and her. I don't want to make things any worse.
But including the other issues I've had with her (that I'll put at the bottom of this post) I am now considering going to our manager anyway.
I agree, she CHOSE this job and the hours. Not my fault.
@SteakExpectations and others, I'll clarify.
I am not considering ringing in sick over this particular one issue.
I am not and would not consider calling in sick because this issue over lunch times has irritated me.
I've not called in sick for years. I've been in this job and working with a severe kidney infection, and with covid (it's remote) although I felt very ill. I was capable of working, It's an easy job, both times albeit I took a ten min break now and again (we're entitled to do this but I rarely do) because I don't like letting colleagues or clients down, and I felt valued and appreciated.
This colleague has now changed that and I don't at all!
I have had a procedure done that's left me with a horribly banging head that I am taking strong painkillers for. This would never usually make me call in sick, I would go into work with a horrible headache provided I was capable of my job, however going in when I know I am going to be nitpicked at and treated badly, while having said horrible headache is a different thing altogether.
Other things that I've had issues with;
I take no breaks aside from my lunch, ever. I asked could I take a break last night for my OOH Doctor to call me about this health issue. She said no. (For clarification I had a similar thing albeit a different health issue occur some months back and our (actual) manager had absolutely no problem with me doing this-in fact that time I didn't actually take a break, I just took the call and told the doctor sorry but if a call came through I'd have to go. We get VERY few calls at that time of night, so unlikely.
I type fast-much faster than colleague, it has been noted many times. She 'told me off' for spending about 7 minutes typing up after a call a few days ago.
Ridiculous, and petty. I responded that I am fast but not that fast.
A different manager set me a task via email, CCing colleague in. I did the task within the hour (despite it not being in my working hours not that that's relevant to this but I am conscientious) and responded, again CCing colleague in.
Two days later I had an email from colleague telling me to get on with the task. It alarmed me as I thought perhaps I'd not done it or forgotten to send note that I had. Nope-I had done all of it correctly and emailed them both. Colleague also hadn't read properly what the task was and told me to 'make sure I do X in future' (X had nothing to do with the task, and I DO always do X).
Set me and (3rd) colleague a task to do, say 20 files of something, so ten each. Told me to do more of them because colleague isn't as fast as me. Now I am happy to do this voluntarily and probably would have offered if I had the time, but don't feel I should be penalised because I type fast and 3rd colleague doesn't.
I took a very important call and had to call through to the emergency services. Time-sensitive issue.
On our system, one can tell when someone is on such a call. Colleague/manager rang through to me while I was on this call, and interrupted for about 5 mins for no reason other than she hadn't bothered to look at my status before realising I was on the phone to emergency services. I had answered this call because I couldn't imagine she'd be ringing me while I was on the phone unless it was absolutely crucial information, but it wasn't.
I think, she's struggling with the job and panicky and taking it out on me. That's what my gut instinct says. I want to go to our manager because I am very unhappy at how things have changed. But I am not sure how to do it and obviously (as is illustrated on this post) manager might think It's sour grapes, although when the job came up I was encouraged to apply but didn't-I simply didn't want it.