Please help us pay to keep full custody of our son

Please help us keep our son safe! My husband had a kidney transplant in September and can no longer go to work due to Covid-19, he’s stuck home on disability and I’m working full time from home trying to support the family with what we can make together. We now have an unforeseen cost of $3,000 we need to pay in order to have an attorney so his son and my step son can be court ordered stay with us full time. We have ALWAYS had his best interest as our top priority and we are terrified as to what will happen if he has to stay with his birth mother who has had no interest in him or what’s best for him. Thank you for taking the time to read this plea for help from two parents just trying to do what’s best for their son.