What is the process of getting a public defender

I am not licensed to practice law in Maryland, and I cannot give you legal advice. However, it appears that your friend may be able to receive legal assistance through the Baltimore Office of the Maryland Public Defender. The web site with this information is http://www.opd.state.md.us/eligibility.html, where it states:
The Office of the Public Defender handles any criminal case carrying a possible jail sentence or a fine greater than $500.00. Eligibility for Public Defender services is determined by comparing a client’s financial condition to the Federal Poverty Guidelines.

Even if your friend is not eligible for services from the Public Defender, their office personnel may be able to provide information about other programs, if any, that provide pro bono criminal defense services.

Go to the local Office of the Public Defender and apply (I would recommend calling first, to see when their intake hours are and what documents you need to bring for income verification). You must apply no later than ten business days before your court date, though the sooner you apply, the sooner you will be assigned an attorney (they will tell you if you qualify financially for their services, as you must be under a certain income level), and the sooner your attorney will be able to begin working on your case.

If your friend cannot afford an attorney, she should request a public defender when she goes to court. There are private criminal defense attorneys, who represent people who pay them. There are appointed lawyers, who are paid by the state or the court system who represent people with no means to hire an attorney.