In Texas, how long from being charged until DA has to take it to the grand jury?

My husband was charged with injury to a child in Texas earlier this year. But with lack of evidence (as my husband didn't do it) the DA has yet to take it to the grand jury. In the meantime, my husband, who is a very good man and has never had trouble with the law, has an open criminal case hanging over his head. I keep reading that the DA has the duration of the statute of limitations to take the case to the grand jury. That would be five years... Do we potentially have to hold our breaths for five years, waiting to see if he's going to have to go to court? That seems so wrong to me. And before you tell me to ask an attorney, we have one. I have called and left message after message asking them to have the attorney or one of his assistance call me back to let me know the answer to my question, but have yet to get the answer, so I was hoping someone here might have an idea. My husband has a daughter from a previous marriage, and she is trying to use the criminal charges to have his legal custody taken away, as well as to force him to have only supervised visits through the duration of the case. This could seriously screw with his life even more than it has. How long do we have to just wait?