-- Who is depicted?

 Nymph in Greek mythology and in Latin mythology is a minor female nature deity typically associated with a particular location or landform. Different from other goddesses, nymphs are generally regarded as divine spirits who animate nature, and are usually depicted as beautiful, young nubile maidens who love to dance and sing; their amorous freedom sets them apart from the restricted and chaste wives and daughters of the Greek polis. They are beloved by many and dwell in mountainous regions and forests by lakes and streams. Although they would never die of old age nor illness, and could give birth to fully immortal children if mated to a god, they themselves were not necessarily immortal, and could be beholden to death in various forms. Charybdis and Scylla were once nymphs.
Other nymphs, always in the shape of young maidens, were part of the retinue of a god, such as Dionysus, Hermes, or Pan, or a goddess, generally the huntress Artemis. Nymphs were the frequent target of satyrs.

-- Technical/Specification about the statue

 Relief is a sculptural technique where the sculpted elements remain attached to a solid background of the same material. The term relief is from the Latin verb relevo, to raise. To create a sculpture in relief is to give the impression that the sculpted material has been raised above the background plane. What is actually performed when a relief is cut in from a flat surface of stone (relief sculpture) or wood (relief carving) is a lowering of the field, leaving the unsculpted parts seemingly raised. The technique involves considerable chiselling away of the background, which is a time-consuming exercise. On the other hand, a relief saves forming the rear of a subject, and is less fragile and more securely fixed than a sculpture in the round, especially one of a standing figure where the ankles are a potential weak point, especially in stone. In other materials such as metal, clay, plaster stucco, ceramics or papier-mâché the form can be just added to or raised up from the background, and monumental bronze reliefs are made by casting.

-- More about the artist

 
We don't know who is the author of this relief, he is actually unknown, there is any information, signature about the possible creator. It seems that there is three fragments of this relief, it's even possible that there is multiple artists for this relief.