Anchia's assertion that seeing an OCer would violate his daughter's right to enjoy the park has a few problems.
First, Anchia omits a few steps. He omits to explain how the gun would emanate anti-enjoyment waves. Since, of course, guns don't do that, he must mean the photons bouncing off the gun would, upon arrival to his daughter's retinas, would violate her right to enjoy the park. No? So, what he really means is that his daughter, having adopted or instilled in her by others the attitude that guns are un-enjoyable, she can enforce her self-adopted attitude on others by denying their right to enjoy the park while also being able to defend the body and life of themselves and others. The false premise being that this is in any way a feasible method of sorting out whose rights are senior. At its core, it means she can enforce her adopted/instilled attitude on others, meaning hers are senior because...well...just because.
Another problem is Anchia's failure to explain why his daughter, if guns are un-enjoyable to see, can't just avert her eyes to look at something enjoyable. He can't mean that seeing a gun once, even on an OCer who is leaving, ruins her whole visit to the park. He can't mean that because it would be a reasonable inference to conclude his daughter is irrationally afraid of guns to the point that once it enters her mind, she cannot let it go. A fixation. And, he dare not mean that. Who would agree that rights are susceptible to the irrational?
On another aspect, the OP doesn't mention the age of the daughter. Did dad create his own objection by instilling in his minor daughter a fear of guns? Did the school system do it? Did dad take any steps to clean up the school system's errors on guns?