Should I let my mom in law adopt my child?

They are already Legal guardians but she says that they want to be the adoptive parents so that she can receive their social security when they die. But from what I understand when you let someone adopt your kid then you give up your right as a parent legally at least. So what should I do

Sounds like a scam to me. The only way she would receive their SS benefits is if they die before she turns 18.
If your child is adopted,you lose all rights to her. Your in laws are now her parents and you have no say in anything. They can even prevent you from ever seeing her again.
Think long and hard about this. You could lose your child out of your life forever.

NO! I don't think you should let them adopt your baby. This is your child, and if you do this I'm pretty sure you will regret it sooner or later. Also, this will scar your child for life. There has to be a way for you to protect the emotional stability of that baby.

When they adopt they have full parental rights. The child legally is theirs just as if it were born to them.

yeah a bunch of strangers will give you great advice.

no thats ur kid! com on now

Why are your in-law the child's legal guardians? Did you land up in jail, and the Court appointed them as the guardians?? You didn't give very much information, but I will do the best I can with what you have told me!
Regardless of the circumstances with this guardianship, there will come a time when you can get custody changed back to you, that's if you want to, and have the means to support the child. One question - where is the father? Why haven't you mentioned him?
I would think long and hard before giving the child over to them and letting them adopt the child! It sounds to me, they want YOU out of their lives AND the child's, FOREVER! You will have NO rights at all if you do it. They can deny you the right to see the kid or have anything to do with him! If you insist on seeing the kid, they CAN and probably will call the cops on you! What about their son, the father of the child, if, in deed he is!? Is he dead or alive, and do they have any other children!? Right off the bat, they are NOT both going to die at the same time, when one dies, the other will get his SS! and vice versa! Then, what about the other children they may have!? Don't they get something? And, whose to say, what they will actually do after they get the papers on the adoption!? You only have their word for that!! I don't know if they are getting any money from the state for taking care of your child, they could be! They could also take your child as a dependant if they adopted him, off their income tax! If your husband is still around, whether or not you are divorced, or he is in jail , he will have to sign those papers as well! What should you do???? Don't sign anything over to them! That bit about their SS doesn't make sense to me! They could live for another 40 years, your kid will be grown up and have a family of his own! He will never see a penny of that!!! Leave things as they are. If it's not broke, then don't fix it! You may come to regret giving in to them!