Most public schools will take the credit, and probably quite a few non-elite private schools will too. Check with your HS, but it should come on a transcript just like a class taken on campus. If any of the schools she’s applying to will accept the credit, just pay for it, even if they’re her safety schools. It can never hurt (unless she transfers the class with a bad grade, but that probably won’t happen, and all my DE classes would let you drop REALLY far into the semester).
You might not need the credit, but you also might – I never thought I’d end up using my DE credit for French because I also took the AP, but the it knocked out my humanities requirement at my public flagship, which was a nice surprise. Some colleges I applied to wouldn’t have given me any credit for it, but some would, and in my case I’m glad I took the chance.
Either way, definitely take the MVC class instead of AP Stat – they’re both helpful, but calculus is more rigorous & it’ll help her in the future.