Have a lawyer review it before you sign it; you're asking for SPECIFIC legal advice, not general information.
This is not legal advice. This response is provided for general information only, as a public service. It is not to be relied upon as legal advice and does not create an attorney/client relationship; nor is it an attempt to create an attorney/client relationship. Consult with local counsel in your jurisdiction about the specifics of your case, which is the only way to gain true meaningful legal guidance and/or representation.
Every State has its own rules that must be followed. In Hawaii child support is calculated using the Child Support Guidelines Worksheet ("CSGW"). Gross income is entered into the form for each spouse. Gross income for purposes of the CSGW would include military base and special pay and allowances, such as basic allowance for housing (BAH), basic allowance for subsistence (BAS), hazardous duty pay, cost-of-living allowance (COLA), selective reenlistment bonus (SRB), retired/retainer pay, reserve pay, National Guard and reserve drill pay, etc.
Do not sign the agreement. You may be entitled to more but no attorney on this site could tell you that without gathering all the necessary documentation regarding your ex-husands income. You need to get a lawyer so that the lawyer can file an answer on your behalf (if a suit has already been filed). If a suit has not been filed, the lawyer can file for you and request tax returns and all income related documents (that are subject to child support)."
The information provided is not advice but a legal perspective and you should schedule a consultation with the lawyer of your choice.