Ever since I killed the old lady (not with DB quest) Constance runs away from me so I can't adopt and I have had no letter either

Have you talked to Aventus Aretino again? I had the same problem, then I realised I hadn't gone back to talk to him. After that everything was good.

Even if you kill Grelod without talking to Aventus Aretino first, you still have to talk to him after killing her in order for the Quest to finish.

If you're not the DB type, then once you sleep and Astrid nabs you, simply kill off the DB.

But you have to finish the Aretino part before Constance calms down.

QUOTE: If you're not the DB type, then once you sleep and Astrid nabs you, simply kill off the DB.

Or don't. You can kill Astrid, but not bother with the rest of the Brotherhood. Or you can kill a captive, but never go to the Sanctuary. Lots of choices.

Or, consider adopting Lucia, Sofie, or Blaise. You don't have to talk to Constance.

I just posted something on this very issue the other night. Don't get me wrong, I feel your pain, but I'm glad I'm not the only one with this issue. VERY frustrating.

u can still adopt orphans in the main cities, there is 1 in both whiterun, wildhelm,and that i have katlas farm, that i have found so far.

Well my second character is no assassin and refuses to knock of little old ladies no matter how mean they might seem, so I guess she will be adopting a couple of waifs from the towns. Braggen is Listener for the Dark Brotherhood, he got the letter for adopting straight away.