Jo had been in the middle of a hunt when the call had come in from the school. If she could have left without worrying that people might die if the creature she was hunting was allowed to run around free for even an hour longer, she would have. There was a reason that she knew she wasn't cut out for a full-time parenting gig but that didn't make her feel any less guilty at not being there right now.
Luckily, Ted had been willing to go down to the school and see what was going on. Maxine was in trouble, she'd gleaned that much from the voicemail. But she couldn't imagine what Maxine might have done that warranted a call from the Principal. Then again, Jo had been in and out of the principal's office herself back in her school days. She supposed that missing your parents could do that to a kid.
Which was why she felt even worse about missing the meeting. But finally, her hunt was done and she called Ted about meeting up with the pair at an ice cream shop (that also served vegan alternatives like soy cream, of course)