Thought you were going to say she is 6'5
According to Wikipedia the average man in the UK is 5'9 and 5.3 ish for a woman, so your mum is a little taller than the norm. How tall is your dad?
I wouldn't worry about it tbh, but then I'm not a midget
My Dad is 6'1 and my brother is 6'2.
I'm beginning to get suspicious.