I would question whether she was even accurate about whether the boys' experience was ruined.
But of course, if she is annoyed and takes that out on DD, then you may have an issue. I'd just be alert.
One thing I sometimes do is, when the musical piece is over, give the former talkers a friendly smile. and maybe make a comment ("beautiful, wasn't it? So fascinating to hear and watch the two pianos interacting!") that has nothing to do with the noise thing. Just to show there are no hard feelings, -and- to show that I'm not the boss of them (i.e., I don't compliment them on finally behaving properly, etc.).
Toots, this is fantastic! It shows the kids you're pleased with their behavior without calling them out by bringing it up again, and you're speaking to them about the performance, as you might with any other (adult) guest there.
Absolutely unbelievable. People wonder why some of us avoid families and family activities like the black death - this is a shining example of why we do. I go to movies in the daytime, midweek, first show, two weeks or more after first release, request no seating by families in every situation when it's possible and patronize absolutely no place where "Kids eat free". This is why many of us act this way. Parents are very different than they used to be and not in a good way.
Edited to add: These caregivers missed a prime opportunity to instruct these boys on how an invited guest behaves. As a guest there are certain expectations of your behavior on the host's part. If you're not a good guest you will stop being invited to things, if you're a good guest and meet your responsibilities then all sorts of new experiences can open up to you. It's all so simple to teach and these caregivers failed their children horribly. Social negligence is my term for it.
Wow, I'm not really sure what to say to this entire post except that's an awfully broad brush you are painting 'all parents' with.
I can't find the part where Rosewater says "all parents." I agree with her post, and although I absolutely agree that it's not "all parents" it's enough parents to infiltrate any reasonably sized public gathering that includes children. Only takes one in a crowd, in fact, and there usually is at least one.
I too felt the broad brush and was quite uncomfortable with Rosewater's post. If you prefer to stay away from activities where there's a chance a child may be there, that is your choice to make, but it's making a big assumption that all kids will (mis)behave a particular way, and that all parents have done nothing to teach their kids otherwise. As a single parent of a child who has accompanied me pretty much everywhere since birth, including full cross-country flights, "kids eat free" restaurants, church services, book clubs, weddings, funerals, movies, casual in-home parties which were mostly adults, large extended-family fancy-dress Christmas dinners, ballroom dance showcases, story-tellers and theatre (live performances), I am proud to have exposed her to many different situations and taught her to behave appropriately in each one. She is a delight to take anywhere, and we've been complimented often by people like Toots that take the time to say something positive. As PPs have said, it's about the parent/caregiver knowing their own child, taking them to places the child can handle, and teaching them how to behave appropriately.
There is no age-limit on inappropriate behavior, as this entire site will show. A teen at a band concert on her way to sit with friends is hijacked by two grown women (she knows) who sit her between them, and talk at her throughout the remainder of the concert. Teenager is uncomfortable, knows the women are rude, is irritated that they're talking at her while she's trying to enjoy the concert. Sadly, nobody nearby told these women to shut up and save the talking for the reception after the concert designed for conversation. (The women weren't invited to this event, which is a whole other post.)
OP, I join many others in agreeing you weren't rude. Clearly someone had to say something to the boys, you did, they listened and were quiet for the remainder of the performance (So what you said was effective!). Their adult was the one who had issues, scolding you for being the one who said something when the whispering was disturbing many people. You were the easy target, when as PP have said, the woman probably realized she had failed by not correcting the boys herself. She was probably embarrassed and thought by projecting her embarrassment onto the boys, she could make you feel guilty.