The more familiar spelling Natalia currently sits securely in the US Top 200, and it has even made two brief appearances in the Top 100 during the last decade. Nathalia, however, lags a good bit behind and has only ranked in the US Top 1000 four times: 2006, 2008, 2010, and 2015. Choosing this spelling will undoubtedly create some confusion, but it still makes a good choice especially if you have a Portuguese heritage.
Two young actresses bear this name: Nathalia Dill from Brazil and Nathalia Ramos from Spain. Nathalia Crane was an American poet and novelist.