Whateverhappened - how old is your Shanice? If she's a teenager or older then it used to be a very popular name and wouldn't have got this response.
If she's little then so what, as long as you and she like it.
It's not my taste personally but I don't hate it, I'm just not keen on the 'eece' sound - I don't like Rhys, Janeese (sp?), Patrice, Elise or Caprice either.