Ha, I am like your sister!
I am just a smidge under 5’10 (177cm) but I’m the second shortest in my family, only my mum is shorter. My dad and siblings are all 6ft+, and actually so is my brother-in-law. Then my own partner and all his family are 6’2 or taller!
Because of my tall family, I often forget how tall I am. It’s so weird. My partner laughs at me having to stretch on tiptoes to reach our (high) top of kitchen cupboards as he is 6’3, but then in the supermarket I’m always being asked to get things off high shelves for Grannies, and people I don’t know well will always say “oh aren’t you tall?” and then I suddenly realise I AM fairly tall, for a woman at least
I should also say that I have a long torso and short legs and that adds to me not feeling tall. I don’t feel tall and leggy and willowy; I’m more like a booby hourglass tall, which again makes me feel shorter than skinny, leggy women the same height as me.