My state return was accepted, and we received the refund within three weeks, but we never received our federal refund and that was six months ago that I filed.

If accepted by the IRS use the federal tax refund website to check the refund status - https://www.irs.gov/refunds

After the tax return has been Accepted by the IRS (meaning only that they received the return) it will be in the Processing mode until the tax refund has been Approved and then an Issue Date will be available on the IRS website.

What is the status of the federal tax refund?