Mariette gave Eli money so she could buy a Super Map perk for herself. 

Mariette's (usable in shop) economy currently looks like... 

Received from lich fight, supposedly: 1 gold, 4 silver, 6 bronze. 
Received after rave event: 1 gold, 2 silver. 
Purchased Super Map for Eli: -2 gold, -2 silver 
Total: 4 Silver, 6 Bronze, 1 Ruby.