If so what place would they have gotten?
First consider how good the Saugus, CA HS girls team is.
17:53 team average at Woodward Park Course (most would consider this course to be about average in terms of difficulty). They are a very good team. Also consider that Jordan Hasay's best time at Woodward park was 17:02 (6 on the all time list - #1 is Julia Stamps 16:43)
Now consider that FM's team avg. at NXN's was 56 seconds faster than Saugus on the same day on the same course, against the same team that ran a 17:53 avg. just a week prior.
If we do a simple extrapolation (by assuming equivalent performances by Saugus at both races) to Woodward Park by subtracting 56 seconds from Saugus's team average we find that FM ran the equivalent of a 16:57 team avg. a woodward!!!! This would put there team average ahead of Jordan Hasays all time best mark on that course.
I think it is pretty clear they would have made nationals but how good could they have been? Top 20? Top 15? Top 10?