9month old niece will not laugh for anyone

Hi guys I'm look for any advice on this for my sister. Long short her 9month old daughter point blank won't laugh or giggle. She'll smile and do normal things for her age but to this date she has never laughed. Mentioned it to Dr's and health visitor and their useless (when she was born they was told by the family her eyes are to far apart and has got a stuck up nose, if you had see her as a baby you'd see there was something not right. They've only now decided there might be something wrong with her face lining). Basically looking for any advice regarding this and is this possible normal and she's just a very stubborn baby.