I adopted my foster son (finally in September after 20 months of waiting)...he came to me when he was barely 2 years old (he's almost 4 years old). Four months after he came to live with me the State was proceeding with TPR when the bparents agreed to mediation (they have 4 visits a year as well as photos, letters, etc.)
We have had 2 visits so far (the bmother missed the 2nd one and the 3rd one was supposed to happen in July but didn't). Our next and last one for the year is this month and I'm anxious to see how my son reacts since he hasn't seen his bfather since April. They aren't bad or scary people just young and not able to parent and we have a good relationship. The bfather's mother actually told me she was glad that I was now his mother!
It was a long process but well worth it. I'm hoping to adopt again someday, hopefully a little girl!
Good luck to you!