There is "no right or wrong answer" when it comes to MBTI-related stuff because it's just a mother and daughter's "personal observations"?
It is to laugh.
Carl Jung — mystical streak notwithstanding — was a believer in the scientific approach, and Myers took Psychological Types and devoted a substantial chunk of her life to putting its typological concepts to the test in a way that Jung never had, and in accordance with the psychometric standards applicable to the science of personality. Myers adjusted Jung's categories and concepts so that they better fit the data she gathered from thousands of subjects, and by the start of the 1960s (as the leading Big Five psychologists have acknowledged), she had a typology that was respectably tapping into four of the Big Five personality dimensions — long before there really was a Big Five. And twin studies have since shown that identical twins raised in separate households are substantially more likely to match on those dimensions than genetically unrelated pairs, which is further (strong) confirmation that the MBTI dichotomies correspond to real, relatively hard-wired underlying dimensions of personality. They're a long way from being simply theoretical — or pseudoscientific — categories with no respectable evidence behind them.
Anyone interested in reading about the validity of the dichotomy-centric side of the MBTI — and about several other issues often raised by people claiming to "debunk" the MBTI — will find a lengthy two-post discussion starting here, and further discussion of the scientific respectability of the MBTI in this post (also linked to in the first linked post).