Are women allowed to wear tzitzis, and if they do can they make a bracha?
Like most time-bound (day-only), "yes-do" mitzvas, women are not obligated to wear tzitzis.
The opinion of some (Targum Yonasan Devarim 22:5) is that all tzitzis inherently fall under the prohibited category of "mens's garb", thus a woman would not be allowed to wear them.
Rabbi Moshe Feinstein (Igros Moshe OC 4:49) and others rule otherwise, that they are not inherently prohibited. Though I have heard some (quoted on Rabbi Frand tape) who prefer that they be pink or frilly or otherwise better-demarcated as NOT a man's garment.
If tzitzis are allowed but not obligated for a woman, the next question (as Rav Moshe writes) is one of intent. If this is a woman's way of doing extra mitzvas to serve G-d, fair enough. If it's a political statement, well then that's a different story.
If all these hurdles are cleared, then the question of whether to make a bracha is the time-honored disagreement regarding women making brachas on optional mitzvas: the Ashkenazic opinion as that she should, and the Sephardic opinion that she should not.