I was watching a podcast that Mayim Bialik hosted.. and she had Melissa Joan Hart on it. They were both talking about women in comedy, etc... and Mayim made a comment about how Judith Light's character on WTB was not writtern/presented well and then said 'that's how things were back then'.
I had to admit I decided to check out some episodes of WTB and I think that Angela was a well rounded character. She had to parent her mother when her father passed, she had to then raise her son as a single mother when her husband cheated on her... so any spark/fun that she might have was suppressed because someone had to take the reigns and keep things going.
The first few seasons really showed her opening herself up to having fun, living life to the fullest, having a close guy friend and being a surrogate mother figure to Samantha... all while having some comedic escapades along the way. I think that Judith Light infused layers into the part that the writers ran with... and man.. she could get a laugh just by one her looks and her tone of voice while reading a line.