By social services, I'm assuming here that the child was placed in foster care?
Not all children placed in foster care are immediately available to be adopted and some never will be. The goal in foster care is **always** reunification with the biological family, if possible. The state will develop a parenting plan with the parent/family to abide by and will give them several opportunities to turn it around. The state terminates rights as a last resort and TPR (termination of parental rights) can take several years with that. They will only terminate rights if the parent/family is unfit to parent. It's only a quick process in extreme cases of abuse (sexual, mentally, physically, etc). Even a parent incarcerated long term doesn't lose parental rights if the child will still be a minor when they're expected to be released (unless the victim of their crimes is the child)
Contact with the child - do you have visitation? Or is the child in foster care with someone known to you, like a family member or friend? If you don't have court approved visitation and this person is allowing you access to the child be aware if/when the state finds out... they will move the child. If this person is a licensed foster parent, they will likely lose their license.
If the mother is fighting to get the child back, that would be a mother that is following the parenting plan to make it happen. That's the only way it happens. I've done foster care a long time and I've had parents that did whatever the state asked them in order to get their kids back, I've had others who did absolutely nothing and others who did the bare minimum to make TPR take longer and get additional chances. I've had some complete the plan and go home, then return to foster care.
A lot of kids adopted from foster care do still see their biological family after adoption. For siblings, grandparents or other relatives they have a strong bond with, the judge can court order visitation post adoption. My daughter, I've had her since she was born and adopted her shortly after her first birthday but she still had a relationship with her biological mom (who died when she was a toddler) and she sees her biological mom's family on a regular basis which consists of a grandma, aunt and a half sister that was parented by her dad (the sisters dad). Her rights were terminated shortly after she was born and her rights were terminated to her older daughter several years before that.