Why is Ally is Part of the cast and not Amy Amy is on the show a lot more then Ally

Here Why Amy will do at least 18-22 Shows Half of them she on at least 10-15 Mintues a Show

Ally is on 10-15 Shows a Year and her averege time frame is 2-5 Mintues a Show sometimes may 10-15 the most to me here is the Real Cast

Ray Romano: Ray
Patricia Heaton: Derba
Doris Roberts: Marie
Peter Boyle: Frank
Bard Garrett: Robery
Monica Horan: Amy

Why need Madylin Sweeten be part of the cast she is not in all the Shows

I guess it's because Ally is Ray's daughter,she was a part of the show since day one.Amy is pretty new in the family.I think if there's a 9th season,they're going to put Amy in the theme song as well.Or I'm going to be unhappy too;)

She for Exmple last Night Amy was on almost the hole Show & Ally was not last Night