What about BOB (and BOB Duallie)? Bike hooks screwed into studs create wall-mounted stroller storage!
Stroller/Bike/Ride-on toy Storage Solution- we installed the Rubbermaid fast track storage system in our garage. Easy to mount the tracks into studs... Then just clip the adjustable hooks on. Bonus feature- we can now park in our garage! Total cost $225.
Sawdust 2 Stitches: Garage Storage
I actually only use a sling, but this could be good for the grandmother's strollers
These garage organization tips will help you create space - by creating zones for your tools, auto and yard supplies you will find that an organized....
Small Apartment Living: With Babies | To The Heights