No, there isn’t. Hope that helps… no, no, that’s really too short an answer, um. So, if you don’t mind, I’d like to expound on the subject a bit.
Sansa’s knowledge of the high harp is an interesting topic, although a slightly confusing one. We first hear that she’s skilled on that instrument from Arya, very early on:
Sansa could sew and dance and sing. She wrote poetry. She knew how to dress. She played the high harp and the bells. Worse, she was beautiful.
–AGOT, Arya I
But then later, Catelyn says something a bit contradictory:
“There was always a singer at Evenfall Hall when I was a girl,” Brienne said quietly. “I learned all the songs by heart.”
“Sansa did the same, though few singers ever cared to make the long
journey north to Winterfell.” I told her there would be singers at the
king’s court, though. I told her she would hear music of all sorts, that
her father could find some master to help her learn the high harp. Oh, gods forgive me…
–ACOK, Catelyn VI
And then, even later, we finally get Sansa interacting with the high harp in her own POV:
Margaery’s kindness had been unfailing, and her presence changed
everything. Her ladies welcomed Sansa as well. It had been so long since
she had enjoyed the company of other women, she had almost forgotten
how pleasant it could be. Lady Leonette gave her lessons on the high harp,
and Lady Janna shared all the choice gossip. Merry Crane always had an
amusing story, and little Lady Bulwer reminded her of Arya, though not
so fierce.
–ASOS, Sansa II
So, Catelyn says Sansa was promised lessons on the high harp, and Leonette Fossoway eventually gave her some… so, did Sansa know how to play the high harp back in Winterfell, or not? Well, assuming that Arya wasn’t completely mistaken (or that GRRM simply didn’t forget how he described Sansa), I think what makes the most sense is that Sansa knew a little bit of the high harp, maybe a few beginner’s songs, maybe whatever Catelyn knew how to teach her herself or from whatever the visiting singers in Winterfell knew. Therefore, she would be prepared to have further lessons from a master in King’s Landing, and Lady Leonette was finally the one to give them to her, albeit more than a year after Sansa arrived in the capital.
Anyway, back to your question. You’re probably looking at Catelyn’s thoughts about promising Sansa harp lessons, and wondering why they never came up in Ned’s POV at all. Well, other than presuming retcon (the easiest answer), the simple fact is that Ned was very very busy in KL. He already had the murder of Jon Arryn on his mind, not to mention Bran’s fall, not to mention the incident on the Trident… and the second he arrives he’s pulled into a High Council meeting about the insanely expensive tourney in his name, and immediately after that he finds out Catelyn’s secretly in the city and she thinks the Lannisters tried to kill Bran. He’s pulled from one thing to another, from one mystery to another, and he barely has a moment to breathe. According to the fan timeline, it’s only about 6 weeks between Ned’s arrival in KL and when he quit being Hand and his leg was injured during Jaime’s attack; and then less than a month from there to Robert’s death and his arrest, much of which he spent heavily medicated. We don’t see him talking over the girls’ lessons with Septa Mordane, we only rarely see him interacting with Vayon Poole who managed his household… All the little details of the Starks’ life in King’s Landing are almost entirely in the girls’ chapters, not Ned’s, because Ned just doesn’t have time for little details. (Brief moments of peace, like the night the three spent in the godswood as thanks for Bran’s awakening, are very few and far between.)
And as for Arya and Syrio… well, Ned walked into Arya’s room after she ran away from the dinner table to find his angry and depressed 9-year-old daughter with a sword in her hand. A sword from Winterfell’s own forge, and from his own blacksmith, that he had no idea existed… and that Arya had no real idea how to use. And because he knows it’s dangerous for them in King’s Landing (and because of his memories of Lyanna), he arranges her lessons with Syrio – and from the context, it looks like he had Vayon Poole search for a Braavosi water dancer in the city (like how Vayon was the one to arrange for the girls’ ship out of KL), Ned didn’t actually go looking for one himself. So… regarding Catelyn’s promise about finding Sansa a harp master… considering how low priority it was, and considering the fact that Sansa wasn’t doing dangerous or upsetting things because of her lack of harp lessons, it’s not surprising Ned didn’t have Vayon look for that kind of teacher for her. Heck, even Cat didn’t bring up the subject when she was in KL, she too had far more important things on her mind.
Also, let’s be honest, the real reason Arya got her lessons with Syrio Forel is because they’re a huge plot and characterization point for her. (Besides the fact that they’re vital to her escape from King’s Landing, and help her survive throughout everything, she’s still quoting him as of TWOW, and probably will until the very end.) Whereas Sansa’s lack of harp lessons are really not important in the grand scheme of things. Or even in her own personal scheme of things. The ones she got from Leonette Fossoway are also not remotely important – I mean, they were nice, and helped Sansa feel welcome among Margaery’s ladies, but if that sentence had been omitted from that chapter in ASOS, it really would have made no difference whatsoever. Like, harp music is one of the few things that soothes Sweetrobin, but is there any mention of Alayne playing? Nope. (Though “Alayne” may not know how to play, but either way it almost certainly won’t be a plot point. Well, probably.)
And being honest again – the real reason Catelyn brings up the harp lessons she promised Sansa is very definitely not for the reader to go “hey, Ned never mentioned them, he didn’t care about Sansa”. Rather, it’s for us to see how terribly guilty Cat feels for having promised her daughter music and culture and a happy life in King’s Landing, and therefore encouraging her to walk into the lion’s den with all the horrible things that actually happened to her. Cat hopes that the gods will forgive her for making this promise to Sansa, for goodness sake. Switching that focus elsewhere feels both inappropriate and irrelevant to me, really it does.
So… while it’s a nice little characterization point that Sansa knows how to play the high harp, and a sad little point that Ned didn’t arrange for her to get the lessons her mother promised her, and a desperately sad characterization point that Catelyn made that promise at all… the fact that the promised harp lessons are not mentioned in Ned’s AGOT chapters or in Sansa’s own should really not be that unexpected.