Help my mom finds the truth to be insult?

my mom is about 57yrs and quite active.. She is always nagging and insulting neighbors.. When I tell her truth that her behaviors is not good, she cries and says I don't respect her. I'm 27yrs married and currently pregnant, I'm old enough to know how to talk to her when she is misbehaving, but she says its an insult and keeps crying... What is wrong with her? Could it be she doesn't like to be told the truth especially? I'm so confused