AF is in T1. She'll have to wait for her luggage there, then walk over to T2 and check in again for her LH flight (or at least drop the luggage) and then clear security. With the current mess that is the MUC baggage handling she might not even have received her luggage in 90 minutes, while LH requires economy passengers to drop their luggage 60 minutes before departure (40 minutes for business). It is very unlikely that she'd make it.
+1
Crazy to attempt something like that on separate tickets.
