I started working at this company more than 5 years ago as an assistant. One of my superiors never trusted my capabilities and never supported my growth, however I got promoted quickly, and after some more struggle I got promoted again at the same time when I changed departments and I am currently managing an office there.
Unfortunately, it's the same company, so I'm not too far away from this person. I know that my current boss (a great person I have in high esteem) has vetoed my ex-boss for the position which I have right now. That said, you can imagine that my ex-boss is not happy at all at me having the position that she wanted to have herself. I cannot guarantee she is aware of my current boss vetoing her, but in any case, she is definitely aware of the result - me having the position, her having to work in the same department as before (her position there is still superior to mine, but I do not respond to her anymore).
Now my current boss is on maternity leave, and after a couple months, I have noticed an increased attention of my ex-boss to everything I do. She sometimes calls me three times a day to ask random questions about random things, or to tell me that a link in the email I have sent earlier was not working. She tries to make suggestions on how I should do one thing or another, and although I can still keep my territory, she is starting to make me really nervous, and that might be one of the things she is trying to achieve. She has also tried to damage my relationship with my colleagues, telling me bad things about a colleague she supposedly heard from another person, which I ignored, because I knew it was not true.
She doesn't have any real power against me, but she seems to be observing my every move, looking for mistakes or clues to give her an excuse to diminish my work, criticize, or simply make sure I'm aware that she's always there.
In this situation I think that it's not me who is having a problem, but her, but it's starting to affect me psychologically. I am nervous about the things I'm doing, as I know that she's going to be the first to appear if there's something wrong.
I wouldn't be surprised if she is also looking for a way to prove that I was not worth the position, especially because the new office that I am in charge with right now has received a lot of positive attention in the company lately (diminishing her position, obviously, as when I was working under her, the performance in the same areas was a lot lower).
We have never really had an open fight, so ignoring her when she asks for some information seems kind of drastic, so at the moment I simply ask her why she needs this info, when she calls, and she starts going around it and never gives a straight answer.
I suppose I should be stricter about that and mark the boundaries of my territory, but I'm used to being nice with everybody and I think that I'm feeding the monster right now. I was also considering talking about the situation with my current boss, but I don't want to trouble her during her leave (although the appearance of my ex-boss is obviously triggered by the absence of my current boss).
Am I doing the right thing? Is there anything else I should do to control the situation?