It's actually pronounced bee-a-TREEZH in Portuguese, a common nickname is Bia (BEE-a). Extremely popular for girls under 12, every other baby is named this. Before, it used to be an old lady's name, but not so much anymore. I have a friend named this (she's 18) and she's less than happy at seeing so many little Beatrizes, since she was the only one in the whole school when we were in elementary.
The emphasis is on the last syllable, not the second. Here's how it works: in Spanish, as a rule, the accent is on the second-to-last syllable. If the word ends with a consonant other than S or N, it's on the last syllable. (These rules don't apply if a word contains a written accent.) [noted -ed]