Does Ava do this all year, or does weather (i.e. cold) affect her behavior?
Scheduled feedings and scheduled exercise (ideally walks) are great means to predict when your dog needs to poop. If you walk Ava at these times, you should be successful at making sure she poops outside.
The other option is to go outside i your yard with her and stay out there until she poops, but walking will facilitate matters.
Either way, don't let her come back into the house until she poops. When she does poop, praise her profusely with keywords and give her a treat. She will catch on.
The process will take a great commitment of time and patience.
I hope you and your husband don't get rid of Ava because of this obstacle. Potty problems are one of the main reasons so many doggies end up homeless and sitting in shelters, rescues, or worse.