Portia is a perfect role-model name, relating to Shakespeare's brilliant and spirited lawyer in The Merchant of Venice, and is now also a Hunger Games name .
Another Shakespearean Portia was the wife of Brutus in Julius Caesar, based on a historical character. In the 1940's, when the name was most used, there was a popular radio soap called Portia Faces Life, the heroine being--what else?--a brilliant and spirited lawyer.
Portia is a recommended choice, even though some people might think you named your child for the car. Just don't spell it Porsche, which may sound the same but has a totally different and -- despite the posh brand -- much more downscale image.
Namesake Portia de Rossi actually started life as Amanda/Mandy.