2010 Prius Completely Dead

welcome! hard to say. take the 12v battery out of the circuit, make sure the jumper is charged, and try again. a bad cell will prevent the jumper from working.
it also could be a blown fuse. how many miles on her?

how does a portable jumper indicate the battery is full?

 

Is there a good connection between the battery and connectors? Or the wiring secured? Sometimes a connection can get loose and then nothing happens.

Do you have access to a multimeter? If so, what is the reading at the underhood jump posts?

 

Read this thread. Hopefully it is only the main fuse and it did its job. Have to be extra careful about jumping a Prius.. Happened to me..but I don't mess with the main electrical parts in a Prius..too dangerous..Had to get it towed to the dealer...I was lucky...good luck to you!!!

100Amp fuse | PriusChat

 

Step by step.
Get a voltmeter. Measure the battery -directly- across the battery terminals. Not the connection cable terminals. You should see 12V or more. Next try the cable terminals. Turn on the headlamps and measure again across the cable terminals. If the voltage is a lot less, remove the cable terminals and clean the lead terminals. Check again. Check the negative cable where it bolts to the body (rear). If all that is good but you don't see 12V at the "boost point" under the hood, you may have a blown 12V system fuse. It's on the positive battery cable, as I recall.

It's pretty simple. If the battery is good something between it and the car is resistive.

 

Testing the battery at the posts with a Solar BA5 will really cut to the chase regarding battery health. A little pricey though. Hmm: only $44 on US Amazon right now.

As noted by other responders, it could also be connections, cables, fuses. Especially with the jump starter not working either. If the jump starter's for sure good, something's not adding up.