Keeping referenced data organized after sorting

I run a Cub Scout Pack, and when scouts fundraise, a portion of the money they earn can go into an "account". Money can then be used to pay for scouting-related activities.

I'm trying to create a simple spreadsheet to keep track of when scouts earn money, and when they've used it.

Here's what I have so far.

It seems to be working fine. The problem is that if I sort any of the tabs by the Scout's name, the data in the relevant columns doesn't stay sorted and attached to the actual scout.

Any tips on how I can best set this spreadsheet up to accomplish my goals?