Transitioning from a baby crib to a big boy/girl bed can be scary for both baby and parents. Parents are worried about baby falling out of the bed at night and Baby can be worried about sleeping in a strange, wide open bed when they’ve gotten so used to an enclosed crib.
Toddler bed rails are a great transition for toddlers who are too big for a crib but too small for a big boy/girl bed. But if you’re like some parents, maybe you forgot (or didn’t know) in the chaos of a new baby to order the essential component of a convertible bed: A conversion kit. Now your crib (in this case, the DaVinci Jamie model 7301Q) is discontinued and the manufacturer (DaVinci, of The MDB Family) no longer carries the conversion kit.
Answer-Wiz did some checking and found this DaVinci Jamie 4-in-1 crib conversion kit available on Amazon:

The DaVinci Toddler Rail Conversion Kit is available in White, Espresso and Gray and has 3.9 out of 5.0 stars. This conversion kit also fits the DaVinci Autumn crib, according to the specifications.

You will also need to purchase the full size bed rails separately. These bed rails convert that crib/toddler bed into a full size bed for your older child. The DaVinci Full Size Conversion Rail Kit also comes in White, Espresso and Gray and has earned 4 out of 5 stars by reviewers on Amazon. According to the manufacturer, you can also use this conversion kit for Anastasia (M7801), Emily (M4791), Jamie (M7301), Kalani (M5501), or Richmond Crib (M2401). Also with your Annabelle Mini Crib (M5998), Emily Mini Crib (M4798), Kalani Mini Crib (M5598), Kalani Crib and Changer (M5591), or Elizabeth II Toddler Bed (M0810).

With the two conversion kits above, you’ll be able to fully convert your DaVinci Jamie 4-in1 Crib and get the most use out of it!

DaVinci Toddler Rail Conversion Kit: http://amzn.to/29Rz2U0

DaVinci Full Size Conversion Rail Kit: http://amzn.to/2a6hOqs 
–Answer-Wiz