"Your son's nose is pointy and big."
This is a valid English translation, but not a good one. A good translation should evoke a feeling similar to the original sentence.
And the Chinese part is not too good either. I haven't seen many people talking about other's noses, not to say describing a nose with 又高又大. Besides, people usually say 鼻子尖 for "nose is pointy", rather than 高. 高 is for 鼻梁 (nose bridge).