Yes she is.
What I think makes this so hard for non-parents to understand is that there's pretty much no days off when you're parenting. Sure, there might be times where you're not obviously doing anything, but you might just be trying to catch your breath or figure out what you're neglecting before getting interrupted by a concerning banging noise.
To exemplify my experience as a dad who works through the week, on the weekends I will try and make the most of things by spending as much time with my kids as I can (4 & 6 for context). Part and parcel with that might entail making lunch.
So I'll ask the kids what they want to eat and I'll get no answer because they're very absorbed in whatever they're doing (i.e. watching tv, coloring, building a blanket fort, etc). So I'll then need to go over to them and re-ask the question, but perhaps this is a time they're watching tv and are far too easily distracted by it to really listen. So now we've gotta find the remote so that we can pause the tv; oh it's behind the couch again, guess we gotta move a couch now. Third time now asking the question and the answer is they don't know and want choices. Ok, so I come up with maybe 3 choices that I'm fine with making at this point in time and they make their choices and I return to the kitchen. It's now maybe 10 minutes after I asked the initial question.
So now, I proceed on making things. My daughter wanted a turkey sandwich so I proceed on making that, but I realize that we're out of cheese which is really going to be an issue for my son who wanted a grilled cheese. So now I've gotta let my son know that I didn't realize that we're out of cheese so he can't have what he wanted, but it's relatively early in the day so he's ok with this sudden change (if this happened after 4 pm, it could've been a real problem) and he says he wants a slice of the leftover pizza.
Ok, so I proceed on making the lunch. The pizza's going to take the longest so I start that and while it's cooking I try and make headway on the dishes in the sink. I also pop on a podcast or something to listen to, but while trying to find something I want to listen to I can hear the kids are yelling at each other over something (probably somebody's leg is on someone else's cushion); the tone isn't at a level where I'm concerned, so I do nothing to see if they resolve it themselves.
I start on the dishes, but probably like 3 minutes after I actually start, the toaster oven dings so I gotta dry my hands and pull the pizza. I pull together a quick turkey sandwich and call the kids to come get them; but I might have to call at least twice if they're really focusing on something. They come get their plates and my son goes out to eat but my daughter stops and says that she doesn't like that I cut her sandwich into triangles because she wanted rectangles. Now this might seem like a silly little thing, but if I totally ignore it, she'll probably be very upset because it's important to her. So I sit with her and we talk about it and maybe figure out some creative way to find rectangles in the triangles or something.
With her accepting the shape of her sandwich, I then get back to dishes. I get 2 plates done and then my son asks me for some apple juice. So I dry my hands again and pour him some juice and remind him to hold the cup with 2 hands. Being proactive, I ask my daughter if she wants juice and she says 'no'.
So I go back to doing dishes. After about 20 minutes, I manage to finish the dishes, but this endpoint is perhaps nearer to an hour after this whole thing started. Also, it's entirely feasible that my daughter will have changed her mind in the middle of this and decided she did want juice. Also, I will have to remind the kids to bring their plates to the counter so that I can wash them.
This is maybe one hour of a typical day for a parent in our house. And oftentimes, it's at least 14 hours of this everyday for our kids.
The point I'm making is that parenting is hard work in every sense. It can be physically demanding (to move a couch, to squat down and talk to a little person), it can be emotionally demanding (to keep your calm when you're getting annoyed, to be in-tune with your own kids' needs to know how to approach them) and it can be mentally demanding (to deal with multiple interruptions plus come up with solutions that might be acceptable to your kids).
At least in America, it often feels like so much of this work isn't perceived as real work because nobody's paying you to do it. But I can assure you it is definitely work and at the end of the day, I'm often far more tired than I would be if I'd just gone to my actual job that day.