Research shows that women are entering the field of physics at a faster rate than the field of chemistry through bachelor's and doctoral degrees. However, STEM studies primarily compare women to men or examine them as a single entity. Therefore, a paucity of research exists that examines what may differentiate women in certain critical and underrepresented fields of STEM education, such as the physical sciences. The focus of this study is to examine differences among women in chemistry in the physical sciences based on background demographics and motivational factors such as academic achievement and experiences ranging from secondary through postsecondary education. This study examines the following research question: "On average, do females who select chemistry as compared to physics doctoral programs differ in their reported personal motivations and background factors prior to entering the field?" This question is analyzed using variables in a logistic regression from the Project Crossover Survey data set through a subset of female physical science doctoral students and scientists (n = 1137). Results show that females who have higher secondary and postsecondary grades and positive experiences in postsecondary chemistry as well as negative postsecondary physics experiences are more likely to enter the field of chemistry as opposed to physics. Therefore, success and experiences in entry-level chemistry courses are critical for female entry into the field and should be further examined. Overall, analyses show that women should not be studied in comparison only to men or as a single entity; they should also be compared to one another to uncover what motivation and background variables influence them to enter a particular field.