How do you know the curriculum isn't challenging? There are things you can look at that might tell a more complete story than what other parents say - I have friends who complain about the curriculum everywhere but they just like to make it sound like their "brilliant" children need more of a challenge when really, the kids are in schools that are just fine and the parents wouldn't be satisfied anywhere.
Look at the graduation statistics for each school - what % go on to 4 year colleges, 2 year college, military, vocational/technical school or the work force? Of those who go to 4 year schools, to where are they getting accepted? How many National Merit qualifiers do they have? What's the average SAT/ACT score? How many AP classes do they have, and what's the average AP score for kids who take the exams (meaning some public schools push AP classes and exams but the kids are scoring less than 3, meaning that they're not really prepared for the coursework).
Is your daughter interested in and qualified for the Math/Science academy? What happens if she gets into the program but decides she's not interested in it or doesn't maintain the grades necessary to stay in the program? Can she then stay in the same school but in a general program or would she have to go to your local school?
How about student life? I went to Catholic school through high school and for my parents, it was about faith and not academics. I went to a school that was excellent for academics, but for my parents, the opportunity to study religion every day and have the principles of our faith incorporated into every facet of our lives every day was what was important to them. It was much more about knowing that we prayed daily, openly talked about God and wrestled with religious issues, could pray openly and sincerely before something important (a game, a performance, a big test), could talk freely about our minds and talents being God's gifts, participated in Mass and campus ministry, went on (and later lead) retreats, and took community service as a genuine call to serve and not just something that was required. Are those the kinds of things that are important to you and your daughter? Does she take her faith seriously and want to be in an environment where faith is central to everything done in school?
Finally, fit is important. When the time comes, she should take the opportunity to spend the day on campus at both schools. One might just feel more right than the other, and that can be as important as what the school looks like on paper. There are "good" kids and "bad" kids at all schools, and there are drugs and drinking everywhere (including this Catholic school you're considering, no matter what people say - it might be well hidden, but it's there).
Those are the kinds of things I would consider, and keep in mind that no decision that she makes is one that can't be changed. For my older sister and me, the all-girl, academically-challenging school that we chose to attend was a great fit and we have no regrets. Our younger sister gave it a try but it wasn't as good a fit for her, so she did public school for 10th grade and then went to a co-ed Catholic school for 11th & 12th, which is where she felt most at home. One of my brothers did 2 years at a co-ed Catholic high school before switching to public and my other brother had learning disabilities that were best served in public school so that's where he went.
Good luck with this process - keep an open mind and remember that you have plenty of time to consider your options!