Even as a graduate student, it was difficult to contact professors on my committee via email. They just get so much email and are so busy that they can not respond to all of it. I used to figure out where they were teaching, and then wait outside the class to catch them on the way out when I really needed to talk to them. So this is what she is up against. I'm not sure calling would be much better. It will vary depending on the person - newer profs might be actively looking for students.
Here's some advice from a prof I know, which could be generalized:
(From https://web.ece.ucsb.edu/~hespanha/ucsb/ToStudents.htm)
1. Please look at my web page (http://www.ece.ucsb.edu/~hespanha). There you will find a brief description of the research areas I am interested in. It may be especially useful to look my publications page (http://www.ece.ucsb.edu/~hespanha/published.html), which I keep updated with all my recent publications.
2.If you find something that interests you and you have past experience (projects, papers, etc.) on that subject and you are applying for a PhD program, please send me an email. In this email, describe briefly what your interests are and what you have done in the area. If you have papers published, please include an URL from where I can download the papers. Please do not send me large files. You should also include your GRE scores, Grade Point Average, and class ranking.
3. If one of my research topics interests you, but you do not have past experience on the area or you are not applying for a PhD program I encourage you to apply to UCSB, but please do not contact me directly. To make sure that I will see your file, please include my name in your Statement of Purpose and also your particular area of interest.
I receive many emails from prospective students and I do not have time to reply to all of them. I apologize for that.
Other useful links:
https://matt.might.net/articles/how-to-email/
https://matt.might.net/articles/how-to-apply-and-get-in-to-g...