Ann-Margret enlists in two episodes of “Army Wives,” the first airing this Sunday, and ET was on the set of the Lifetime TV series to get the cast’s take on what it was like to work with the Academy Award-nominated actress.

“She was just amazing, so much fun, so professional, so gorgeous and really great to work with as an actor,” Kim Delaney, who plays Claudia Joy Holden, tells ET.

Ann-Margret, who plays Aunt Edie, unexpectedly shows up on the base to visit her nephew Major General Michael James Holden (Brian McNamara) and his wife Claudia Joy. Claudia Joy had planned to host an annual Mother’s Day brunch for families who are missing loved ones, but when Aunt Edie comes to town unannounced, the Holdens have to change their plans.

“When you get the script and you find out who is playing the role — that is exciting. When we found out Ann-Margret was playing my Aunt Edie, everyone on the crew was, ‘Do you know who is playing your aunt?’” Brian tells ET. “She is fantastic. This is the second time I have worked with her. We did a series called ‘Four Corners’ about 10 years ago. She is just so pleasant, still so beautiful and she fit right in. We have a fantastic group here and we have a lot of fun, even though we are telling a lot of dramatic stories.”

Also on Sunday’s Mother’s Day episode, Joan (Wendy Davis) is stuck overseas but that doesn’t stop Roland (Sterling K. Brown) from finding a way to make sure she feels loved and appreciated for the special day.

That means that Wendy didn’t have any scenes with Ann-Margret, but she did have the opportunity to meet her. She recalls, “She was full of life. She just fit right in with the girls. That is one of the fun things about ‘Army Wives.’ You get to meet some of your acting heroes.”

But Sterling did get a chance to work with the acting legend. He says, “I can remember watching ‘Bye Bye Birdie,’ ‘Viva Las Vegas’ or some of her other films. She was the bombshell of her time and is still so beautiful inside and out. She was such a sweet and gracious lady. She really classed up the joint around here for the seven or eight days she was with us.”