Shotgun overhead on a boom is the way to go with something like this.
Rules of thumb working with kids - never give them anything they can hold, and never use wireless lavaliers.
Take the rode mic off the camera and put it on a boom stand and cable it back to the camera. Keep it high enough so that it remains out of shot.
The EIN specs of the microphone don't really make much sense as this parameter usually only refers to a preamplifier and is measured by grounding a 150 ohm resistor across the input.
Additionally, dBA is an acoustic measurement not an electrical one so again this doesn't make much sense when used in an electrical context unless you are picking up the ...
Would a USB hub help? - Probably not but possibly.
First step, ensure both ends of the XLR are fully seated on their connections. Ensure that the +48v is engaged and the LED light shows that it is on. Check that the microphone does not have a "pad" button that is engaged.
While talking into the mic adjust the "Mic Gain" until the LED just above it is a ...