Drum brakes have an auto adjustment ratcheting like device that spreads and locks the position of the shoes every so much bit of travel to take up the slack of the missing pad material as they wear. You'll need to disengage that and manually reset it to allow the shoes to be pressed backwards. You may need to open the bleeder valve and allow fluid to escape as well so you can push them back against the fluid pressure. Been a while since I've done anything on drum brakes so my info may be off a little. If you get lost with all the clutter of parts, you can always take off the other wheel to see where they go.
After that you will definately need to completely bleed the brake system, at least that one wheel. No doubt she lifted the brake pedal after that and sucked air back into the system if it opened up the system enough to spray fluid or if the bleeder was open. Don't forget to top off the fluid level in the master cylinder as well, and check and recheck it constantly. If enough fluid was lost that the master cylinder got too low, you WILL have to bleed the entire system at all 4 wheels and if it gets low again while doing that you'll have to keep starting over. Make it clear to the person helping not to let the pedal up a single mm unless the bleed valve is closed and you tell them to.