Yes, it is possible. But, what would help is to assist her in identifying if it is really an issue of gender identification or sexual attraction to the same sex or simply curiosity. Individuals both who are gay and who struggle with gender issues generally know/feel this way from early on in their life (it does not happen over night)
You may want to explore with her what may have taken place two weeks ago when this issue became apparent to you i.e did she see something, spoke to someone about it, read about it, has a friend/peer who's actually struggling with this and she wants to identify with that peer, etc.
When you speak to her, you're trying to gather information not make the interpretation for her. If possible, try to be as objective as you can. You want to gain her trust not to rebuke her or to evoke shame and guilt within her which, would be the most harmful in this case. Encourage her to identify what this means to her. Is she afraid/anxious, confident/certain that she's found a part of herself that is new to her, etc. Is she able to identify if this is triggering a sexual response or a psychological one ex: male are stronger and more accepted than females in certain areas/jobs, etc.
Hormones would not necessarily evoke gender identity confusion. Increased level of testosterone in women would make them feel more assertive or appear aggressive as well as have a heightened libido. These are mostly connected to sexual arousal/intimacy issues. In home hormone test
If you believe that she is not 100% comfortable talking to you about it, then you may suggest that she talks to a professional who specializes in working both with gender identity as well as sexuality issues.
Gender Identity Disorder And Psychosexual Problems In Children And adolescents Kenneth J. Zucker
At the moment it would be best to explore these feelings/thoughts with her not suppress them. You may tell her these feelings can go away. Even if she is bothered or telling you she is uncomfortable feeling these feelings, emotions are strong indicators that something is taking place internally that triggers them. You can encourage her to keep a diary and then a dream journal to record what insight she may be getting from these experiences. You can reassure her that as individuals grow up, their ego/mind is trying to make sense of different things both internal and in one's environment. When she brings the topic, let her know that there is nothing to feel ashamed about, that people go through different stages as their personalities/egos develop and the more someone knows about oneself the better. Experiential activities such as art or dance or even her sports may be able to shed light and bring an integration of these feelings/thoughts. Help her make a differentiation b/w thoughts and feelings and how thinking can evoke emotional responses. At this point, you may even encourage her to learn as much as she can about this issue. In Jungian psychology the terms Anima and Animus explain that each individual holds the polarity of male and female within themselves and can use these energies for self expression. An example would be a male who is a cook or a female who is a fire fighter. In Native American indigenous rituals male were even encouraged to learn as much as they can about the sacred feminine. Appreciation of female beauty is not indicative of lesbianism. It may be that she's developing an ability to appreciate what she observes which can help in professions such as beautician, designer, etc.