I saw Melissa Gilbert in the musical Little House on the Prairie (I got a pair of free tickets for helping with a pre-show event), and she did start crying when the audience stood for her at the end, but when the other cast members wanted her to speak to the audience, she insisted someone else do it, because she was too choked up and didn't want to cry further, so I don't think she's particularly interested in big public emotional scenes either. I think what got to her was perhaps that she was in the middle of Little House country--the real deal, not the sets she'd spent her childhood on--and she knew the Wilder books are darn near local versions of holy texts, so she took the standing ovation to heart (though, truly, in the midwest, the joke is that people will also give a standing ovation to a good corn crop). I was impressed that everywhere the show went on tour, members of the cast worked on Habitat Humanity houses, helping to build new little houses on the prairie, and part of the ticket sales for the show was given to Habitat and part to Seeing Eyes for the Blind, the guide dog organization, as sort of a tribute to Mary Ingalls.
I also thought it was very funny that the first entrance of Nelly Olsen was greeted by an adult male voice booming out, "It's NELLY!" followed by raucous applause. The young woman who played Nelly was good, but she had the audience before she opened her mouth, just by virtue of the role, even if she was Laura's nemesis.