I probably wouldn't ignore the behavior. I mean, I don't specifically have a chore situation, but when my daughter (who also is seven!) whines or complains, my intended response would be to listen to her. Sometimes I just get irritated and react, but at whatever point I can connect to myself, I then start listening & allowing, no longer resisting (through irritation or reasoning with her or pointing out problems with her logic...)
So yeah, I would choose "do something about it" over "ignore it," but for me doing something wouldn't mean coming down on it or doing something in order to stop it. In my experience, if I take a hard line that the complaining or whining is unacceptable or unreasonable, it is likely to prolong it more than anything else.
I don't like whining, it can make me quickly agitated, but I believe that whining and complaining is a signal that something is off for a person, so remembering that can help me think of it as less The Problem and more a signal or symptom of some underlying problem. (This is another reason I wouldn't just ignore it, because it's pretty much a call for help or request for connection around an issue.) I don't have to figure it out and know "for certain" what is going on, just shift my relationship to the whining/complaining behavior enough through knowing that something is going on.
Anyway, if I feel annoyed or irritated, chances are I am taking on something (like a feeling like this is some problem I have to solve, a "good mom" could fix it) and then feeling edgy & annoyed when it's clear that I can't fix things because my kind reasonableness doesn't "work." For me, this is a time for reflective listening (just letting my kid have her feelings & thoughts, and containing them/her with my acknowledgment & acceptance), not the time for making suggestions, giving explanations, trying to reason with her, or solving/stopping things in any way.
I think this situation is one of those times when "the child owns the problem," and the whining & complaining & general irritability (all of which is usually part of a victim mindset, locating blame AND the solution/key for one's happiness outside oneself) is probably a signal of being stuck somewhere in the process of coming to terms with not being able to have/do what she wants, or having to do something she doesn't want to do.
It's just like having feelings about encountering a limit & not being able to change it---there is a struggle & then a grieving process when the person deals with the reality that they couldn't change what they wanted to change, and has to offload frustration, grief, disappointment, the rage that can come from feeling powerless, etc. in order to regain emotional equilibrium. Resisting the expression of these feelings (even just through trying to explain or fix things) tends to prolong the process or get the person stuck in defensively insisting on these issues, while reflective listening, (even just sympathetic & understanding silence and acknowledgment), facilitate process, itself.
Just being with & allowing the feelings seems to open things up & at that point, kids seem able to find their own solutions or just to resolve their feelings & move on (even with no "answer" or change in the external circumstances.)
So hearing her, having kind of a "Yeah" or "I see" sensibility, with enough reflecting that it's clear that you actually "get it," and not needing to answer it or take issue with it, may help most of all. You don't have to "agree," just to be able to see how her thoughts & feelings make sense from her point of view. It's not really something you "do to" her at all, and the effort is likely to backfire in big ways if it becomes that rather than an attitude or an orientation toward, or a kind receptivity that emerges out of connection & acceptance.