Just so we're clear in advance: this is Rosemary, making her debut at the English royal court.
In point of fact, none of the immediate Kennedy family expressed public remorse/criticism for inflicting the lobotomy on Rosemary--at least not directly. Now, whether they all believed it was the right thing to do, whether they believed it was the utilitarian thing to do, and whether they indirectly expressed a sense of failure or anger--that is, shall we say, a rather nebulous topic in biographies of the various Kennedys.
One camp, headlined subtly by Doris Kearns Goodwin and like a sledgehammer by Laurence Leamer at the two poles of the spectrum, sees in Joseph's actions after the 1941 "surgery" a man seeking solace (Goodwin) or who understood he had committed a major sin (Leamer). Joseph initially placed Rosemary at a rehab/care facility called Craig House that had an excellent reputation and charged the fees to back it up. Joseph's biographer (and actual professional historian) David Nasaw shows on the basis of letters sent to family members that Joseph most likely visited Rosemary several times over the course of the 1940s, although it became horribly clear she would regain any more of what had been wrenched away from her than some motor skills. Joseph's words to his family are noncomittal--"looks very well" "feeling quite well." In 1949, probably owning up to the long-term prognosis, he arranged a special place for her at an institution/"school" in Wisconsin run by Franciscan Colettine nuns. As in, he gave buckets of money to the place for special accommodations for her.
Of course, while Joseph was doing all of this, he was keeping his family away from visiting Rosemary themselves, and misleading them about the shockingly awful lobotomy results. Whether he was trying to insulate himself from his wife Rose's wrath, or protect his family from seeing what he'd done, OR protect his family from seeing that what he perceived as a last-ditch attempt to help her had still failed, is left to question.
For his part, Nasaw, whose take is generally considered among the most equitable, refuses to make a judgment call on whether Joseph believed he had done the wrong thing. But although he won't go as far to paint Joseph as a father with at least some sorrowful feelings for his daughter as Goodwin, she is much more brutal about the effect this had on Rose. She tells the story of Rose asking her friends over and over, "Why didn't you tell me?" only for her friends to say, "we didn't know either." In her memoirs, she wrote:
The operation eliminated the violence and the convulsive seizures, but it also had the effect of leaving Rosemary permanently incapacitated. She lost everything that had been gained during the years by her own gallant efforts and by our loving efforts for her. She had no possibility of ever being able to function in a viable way in the world at large.
I'm not sure how this is not generally accounted a direct attack on Joseph's decision, but it does not seem to be? But then, this may be a pattern. There is one letter where Joseph comments more extensively on Rosemary's existence in the world, rather than breezy mentions of doing well. In 1958, he wrote to the nuns of St. Coletta's expressing his deep gratitude for their "persevering kindness" towards Rosemary. And pretty much every writer quotes the same lines:
I am still very grateful for your help. After all, the solution to Rosemary's problem has been a major factor in the ability of all the Kennedys to go about their life's work and to try to do it as well as they can.
Nasaw offers zero commentary; Goodwin suggests he is expressing sorrow for the outcome, and maybe or maybe not the decision. Disability rights advocates, on the other hand, have pointedly asked, "Is Rosemary not 'all the Kennedys'?" And in Joseph's words, they find him saying that isolating Rosemary in Wisconsin, away from the world's knowledge and from her own family, was the only way that the rest of them could be successful. That is to say: people with cognitive disabilities are a problem to be solved, and to be solved by exclusion.
Of course, the rest of the Kennedys went on to champion mental health services and services for people with cognitive disabilities on the national and even international scale. Rose Kennedy was orchestrating donations for child neurology research through the Kennedy Foundation into the 2000s--and, for whatever bitterness she held, ensuring that things with a name attached would memorialize Joseph as well as herself. Jack signed a series of mental health services bills into law; while they ultimately resulted in massively inadequate care for a lot of people when the requires facilities were never built (a failure of money and a crime of NIMBYism), Senator Daniel Moynihan suggested that Jack would have flipped tables in the White House if he thought people like his sister would not be taken care of. Eunice Kennedy Shriver's activism in creating an arena for social life and growth in the Special Olympics I've discussed elsewhere in the thread. Ted Kennedy was pushing for mental health insurance coverage parity until the end of his life. And people generally agree that the Kennedys did a lot to raise awareness of the actual, real existence of people with cognitive disabilities and mental health disorders--and more to the point, of starting to crack the stigma on talking about them in the first place.
They shouldn't get all the credit. The 1950s saw mothers (and some fathers, but mostly mothers) of children with Down's syndrome banding together in parents' groups--ARC is founded in 1951--and did a lot to cast off the idea that a diagnosis of developmental disability was the absolute end for the togetherness of the family. On the other hand, you can't argue with the impact of the visibility--and pocketbooks--of the Kennedys.
I'm not a cynic who sees the other Kennedys "using" Rosemary as a platform, or rather, of "taking advantage" of her. Nevertheless, I have to wonder why--in the face of all the crusading--Rosemary herself was never allowed a presence. The lobotomy destroyed the person she had been...but there are all kind of people at all levels of cognitive ability in America. So I think it's a real question that both historians assessing the situation and disability rights advocates have to ask: were they (and hence, people in a similar situation) keeping Rosemary out of sight because of guilt, shame, unwillingness to criticize the family patriarch? Or did they conclude based on what they knew of Rosemary's own thoughts and hopes, rather than their own, what she would have preferred...had she only been able to voice them herself?
Further Reading:
Can I ask a side question? I've heard that JFK was a big proponent of the community mental health act because of how his sister was treated in state institutions. Is there any truth to that?