In tonight's episode of Grey's Anatomy (April 30th), Katherine's character Dr. Izzie Stevens receives an unexpected visitor to her bedside as she battle cancer. Much to Izzie's surprise, mom Robbie heads from the trailer park to visit her daughter at Seattle Grace Hospital. Ronnie, played by NYPD Blue alumna Sharon Lawrence, has been chatting to the press about her colorful turn as Izzie's unconventional mother and working with Katie on some very emotional scenes.

TV Guide

TVGuide: Is Izzie happy to get this surprise visit from her mom?
Lawrence: No, she has no idea that her mom is even aware of her circumstance, much less is going to be coming to Seattle Grace. That's an interesting thing to examine, that when someone is that ill, it's a challenge to share it with anybody, much less a parent who has not been particularly responsible. I know a lot of folks who have chronic physical conditions, and one of the biggest issues is how it's going to affect the rest of your family, and what it means to manage their emotions.

TVGuide: Izzie obviously has her reasons for not wanting her mother to know exactly what's going on.
Lawrence: Because someone like Robbie can be much more of a drain than a support, no matter how well-intentioned. I believe that Robbie with every fiber of her being wants to mother Izzie; the question is whether she's capable of giving the sort of care that someone in Izzie's condition really needs.

TVGuide: As the mother-daughter scenes turn serious, was it easy to go there with Heigl?
Lawrence: I tell you, from the first minute that we started working in the rehearsal together, I recognized how open and comfortable she is as an actress. She made it so easy to get to that level of emotional and physical intimacy right away. One of the reasons I've always been attracted to her work is that she just can't fake it, she's so honest. That made my job so easy.

Click here to read the interview in full.

Entertainment Weekly

Michael Ausiello: I just hung up with Sharon Lawrence, who guest stars this week as Izzie's trailer-trash mom, and she had some interesting things to say about working alongside Katherine Heigl. For starters, they didn't get a chance to speak to each other prior to rehearsing their first scene, which called for Lawrence to practically tackle Heigl in her hospital bed. "The first thing I did was barge in and hug her," Lawrence explains with a laugh. "I could tell right away she was present and not guarded. We got to know each other as the day went on, because we would have time to talk about other things while we were waiting to work. It's an odd thing we do for a living. Sometimes you have to get very close to somebody right away. That's why I was so grateful for her openness and warmth, and it's because of that that we were able to make physical and emotional choices that really conveyed the intimacy these two had. She is such an honest and open actress. There is not an untrue bone in her body as an actor, and it made my job so easy."

Despite all the media attention focused on Heigl's uncertain Grey's future, Lawrence insists she came into the job with no preconceived notions about her TV daughter. "I would never judge the situation from the outside," she says. "I've been around long enough to know that the outside does not have all the facts. All I care about is that the storyline is served well."