Yes, he had noticed that something had been off with the way this lady looked. Something was strange about her but in a strangely familiar way. How could he have missed it. While her general features were normal. An elderly, somewhat short lady of mixed-race descent. It was the length of her extremities in proportion to her body that gave it away, but only if you knew what to look for.

I'm going to rearrange these sentences and split it into what would be the end of one paragraph followed the start of the next paragraph, as follows:

Yes, he had noticed that something had been off with the way this lady looked. An elderly, somewhat short lady of mixed descent, something was strange about her but in a strangely familiar way.

How could he have missed it?! While her general features were normal, it was the length of her extremities in proportion to her body that gave it away, but only if you knew what to look for.