OK, so she appealed the custody order. That appeal is either stayed, or dismissed, or ongoing; you need to go out. It doesn't sound like she's appealing the child support from the second order.
Enforcement is either with you or with the Family Responsibility Office. You should do the latter. They are slow and a brutal bureaucracy, but they get the job done in time and it doesn't cost anything. If you haven't done the FRO registration package, then go to court. Get a copy of the package and check that the Support Deduction Order went from the court to the FRO. It should have. Also, someone should be taking out and issuing that order; ask your lawyer about it.
It would be very unusual for the order to say that the payor has to pay 50% of their income for child support. In fact, I've never seen that. Support is, 99.9% of the time, a monthly amount based on the actual or imputed income of the payor. I suspect that you're confused by something you heard, that the FRO can take 50% of a person's income towards child support and arrears. That's an enforcement measure, but the amount of support that's due is going to be a monthly amount.
If income isn't being disclosed, or the payor isn't complying with an order (other than the actual payment of support, which is with the FRO for enforcement), you can bring a motion that she be held in contempt. That's an extraordinary thing if successful, but you might well have enough for that. When talking to your lawyer, ask about that option. If you have evidence of unreported or under-the-table income, gather it together. That can include her mentioning work or income on facebook, advertising for a service she's providing like housecleaning or escorting, whatever you can find.
But the first place to start here is to get a copy of the final support order as issued, get the FRO regsistration package and complete it and send it to them, and confirm with the court that the SDO has gone to the FRO.
Does that make sense? Please reply with question or comment. That's the best anyone can tell you until you have the court order in hand and can tell me what it says.
If I've answered fully, I'd appreciate a positive service rating please. But I'm here if there's more to discuss.