My mom and sister are ISFJs as well and I differ from them a lot. They are both very neat people who love cleaning while I can't stand chores. I do them but I struggle to. Both my sister and mom actually enjoy doing chores. They are both very grounded people who don't enjoy fiction as much as I do. My mom loves talking on the phone while my sister is pretty social as well. I'm not at all. My sister watches simple comedies that make her laugh, but I look for deep emotional resonance in entertainment. I like books that reflect who I am and what I feel. Some of my favorite books are Catcher in the Rye, Perfume, Mysterious Skin and IT. I love these books because they are highly sentimental, weird and dark. I love deeply sad music that is similar to my book taste. I'm highly apathetic and don't seem to care about anything. Both my sister and my mom tend to think about others while I think about myself. I do think about others but can be pretty self-centered.
If it helps here are my cognitive function results
extraverted Sensing (Se) ************** (14.5)
unused
introverted Sensing (Si) *************************************************** (51.1)
excellent use
extraverted Intuiting (Ne) ********************** (22.6)
limited use
introverted Intuiting (Ni) ************************ (24.2)
average use
extraverted Thinking (Te) *************************************** (39.8)
excellent use
introverted Thinking (Ti) ************************ (24.3)
average use
extraverted Feeling (Fe) ************************ (24.5)
average use
introverted Feeling (Fi) ************************************** (38.8)
excellent use
If it helps here are my cognitive function results
extraverted Sensing (Se) ************** (14.5)
unused
introverted Sensing (Si) *************************************************** (51.1)
excellent use
extraverted Intuiting (Ne) ********************** (22.6)
limited use
introverted Intuiting (Ni) ************************ (24.2)
average use
extraverted Thinking (Te) *************************************** (39.8)
excellent use
introverted Thinking (Ti) ************************ (24.3)
average use
extraverted Feeling (Fe) ************************ (24.5)
average use
introverted Feeling (Fi) ************************************** (38.8)
excellent use