Is this a Hindu Goddess? If yes which one and what do they represent?
This looks more like a Thai goddess rather than an Indian/Hindu one. In fact it may not even be a goddess but just a dancing girl as this is a really popular pose from Thai traditional dancing as evident from the below image:
Generally it is shown for the kinnaris who are half human-half bird divine beings in South east Asian mythologies especially Thailand:
BTW I found something similar to your pendant being advertised on ebay labeled as a Thai dancing goddess:
Most likely it is just a dancing girl or kinnari being advertised as a goddess.