From what you told me, this does not even sound like it is a possibility. Do we need to wait until she is 18?
that is up to the girls mother and adoptive father (you don;t seem to say where he is in all of this)

I do not understand why my husband would have to adopt his own biological daughter when he didn't even know he had one to start with.
there is the biological father and there is the legal father. They aren;t always the same man. In this case, your husband was never legally determined to be the father so he is not the father, legally. Additionally, another man adopted the girl so he is the legal father to the girl. If your husband is determined , legally, to be the girls father, he may not have to adopt his own child BUT many states do not like to disrupt a childs life with such matters. The fact they already recognize certain people as their parents can outweigh the fact that somebody else is the bio father.

Why doesn't he have any rights?
Because as it stands, he is not even the bio father, to the courts. A quick look at Arkansas laws shows there is no statute of limitations to have paternity established so if your husband wants to be legal dad, then he will need to initiate an action to do so.

[QUOTE] Will he ever be able to get to have rights or will her mother be in complete control which means that we have to step on broken glass every time we talk to her just so father and daughter have a chance to really get to know each other?[/QUOTEYour husband and the girl are legal strangers, as things stand. Until he sues in court to have paternity established, that will always be that way.

Should we hire a lawyer or wait it out being that the courts are slow and we only have 2 years until she is legally an adult?
that's up to you. If it were me, I would, at least, hire an attorney to research this to see if there is anything your husband could even do. Then weigh the options and make a decision.

The worst part is that we know that we have a lot to offer this child who has dyslexia, homeschooled by a parent that only gives her books and papers to do while she is at work, doesn't really teach her, and is on a fourth grade math level. I feel like we could really help her but our hands are tied. Mom comes out with different stories every time we try to get information, so we will never know the truth.
Until and if this ever gets in to the courts, remember, you are legally nothing to this child. Your husband has absolutely no rights to demand anything. Her mother and father are the people who the courts will support in this situation because...they are her parents.

One thing to rememeber; if your husband is determined to be the legal father, he will then be liable for child support.