Betty Garrett was led to believe that the show was going to end with season seven, so she signed up for a play, only to find out that Penny & Cindy agreed to do one more season.

So, the producers wrote the Edna character out by saying she'd run off with another man, leaving Frank behind.

I felt this was so wrong. They could have just said she left town to tend to a sick relative and let it be that. They could have shown Frank talking to her on the phone, and maybe if she was able, Garrett could have made a guest appearance.

I don't think Edna would ever leave Frank that way, and it was a very downbeat moment in a very troubled final season.

They didn't showed how Frank felt after she left. When Shirley left, everyone was sad.

They didn't showed how Frank felt after she left. When Shirley left, everyone was sad.

If I remember correctly, there was an episode in the final season after Shirley left, where they addressed the issue and they showed how Frank felt.

As I recall, he was pretty angry/depressed about it.