In my experience, male Maltese tend to be more attentive and more accepting of other pets and children. Females tend to be more independent and protective of their family members (including you!) These are generalizations; individual personalities will vary.
Another interesting fact about Maltese is that males tend to bond better with women in the home, and females tend to bond better with men in the home. Again, this is a generalization, but one that is something to consider.