Your female ancestors are simply tougher to trace than the men in your family.
Do you have female ancestors on your pedigree chart for whom you don't have a maiden name? Or perhaps you have female ancestors for whom you don't know the names of their parents. Maybe you have female ancestors missing a first name, not to mention a maiden name and parents. You're not alone; we all have them.
Your female ancestors are simply tougher to trace than the men in your family. Their maiden names disappeared with their marriage. Their roles in history have been less celebrated and less recorded. Women led private lives, unlike their husbands who led public lives. Men served in the military, they bought and sold land, they sued and were sued, but women had few legal rights until the late 19th and early 20th century. When a woman married, everything she owned became her husband's, even the clothes on her back. Unless she remained single or was widowed or divorced, she couldn't enter into any legal contracts without her husband's consent, whether it was writing a will or buying or selling land she inherited from her father. Even the legal custody of her children belonged to the father.
But that doesn't mean you should give up—or that you should be satisfied with finding your female ancestors' maiden names, or their parents' names, or when they were born and died, or that they gave birth to several kids.
Historian Elizabeth Fox-Genovese said that the "history of women cannot be written without attention to women's relations with men in general and with 'their' men in particular, nor without attention to the other women of their society." From a genealogical research standpoint, we might say the same thing. Those who successfully find the maiden names and parents' names of female ancestors aren't focusing their research efforts on just the woman in question. They're also researching the woman's husband and every person he comes into contact with.
Some female-ancestor mysteries are easier to solve than others, but there's no magic bullet. It takes diligence and persistence, and you have to exhaust all the records in the area where a woman lived. In particular, you must broaden your research to the men she was connected with, simply because men left more records.