Yes they can if they seek to terminate your parental rights. If they file a petition in childrens court you should be eligible for family reunification services. If you do not comply with the case plan then they can seek to terminate the family reunification services and your children will eventually be adopted assuming they are considered adoptable. Some kids, due to their age or disability, end up being placed in the foster care system until they reach the age of majority because they are not adoptable. You need an attorney to represent you and it should be someone that knows juvenile dependency law, not just a family law attorney.