As long as you show up in court, your actual income from your tax return will be used. It's not showing up that can be dangerous to your financial health! The courts take lies as fact if you are not there to object.
Your ex should have her income imputed to full time at the minimum wage for child support calculations.
Also, don't ever let logic be part of your decision making process when it comes to anything to do with family courts. Logic often does not apply. Heck, folks have paid years of child support, but didn't write "child support (month,year) in the memo and have had to pay it all again as the courts have called it a gift if not exactly identified. Can you imagine if you overpaid your electric bill by $50K and they wouldn't refund you, calling it a gift? It would make the nationwide news.....but not when it comes to family law.
You can calculate what your child support should be by googling "child support calculator (your state). Some states have the exact calculator that will be used. Others are not official, but are fairly accurate.
If you make more than you did when it was last calculated, expect support to increase.