I felt they wanted to continue with the theme, Shamsher to not know his daughter has accepted RK, I feel the CV's purposefully made Madhu have that angry expression because Shamsher would be sitting on the sofa against the wall watching RK and her perform the puja, because they want him to continue to feel she needs him to rescue her from this marriage. But to be honest it was strange she was angry, even if RK boots Sikki and Dips from leading the puja or that RK won their battle for her to change out of Dips saree, is that a reason to have a sour face whilst performing the puja? It's all because they want to convince Shamsher Malik that he must strike again to kill RK. So mentioning her first name Madhubala that's all.
Madhu could never say Madhubala Shamsher Malik now that she is married (we who have seen everything after her marriage, Malik hasn't), but leaving just her first name, in the context of mentioning her parents insinuates that she wanted to say her maiden name, but she is too feared of recriminations by RK to say it...it's all to feed into the next part of Shamsher trying yet again to kill RK to save his daughter.