I had a exchange student so how can I claim her as a dependent

[xmasbaby0]

You cannot claim an exchange student as a dependent.   You might be able to enter a charity donation for hosting a student.

From the IRS

https://www.irs.gov/publications/p526#en_US_2012_publink1000229664

Expenses Paid for Student Living With You

You may be able to deduct some expenses of having a student live with you. You can deduct qualifying expenses for a foreign or American student who:

1. Lives in your home under a written agreement between you and a qualified organization (defined later) as part of a program of the organization to provide educational opportunities for the student,
   
2. Isn't your relative (defined later) or dependent (also defined later), and
   
3. Is a full-time student in the twelfth or any lower grade at a school in the United States.
   

You can deduct up to $50 a month for each full calendar month the student lives with you. Any month when conditions (1) through (3) are met for 15 or more days counts as a full month.

[MaryK4]

Generally, you cannot claim a foreign exchange student as a dependent on your tax return because they typically do not meet the IRS residency or relationship requirements. However, if the student was placed through a qualified non-profit organization, you can claim a charitable contribution deduction for hosting them. You can deduct up to $50 for each full calendar month (15 or more days) the student lives with you.  This is an itemized deduction reported on Schedule A. If you take the standard deduction, you will not receive this benefit. 

How to Enter in TurboTax Online

Follow these steps to enter the charitable deduction: 

1. Sign in to your TurboTax Online return.
2. Search for "donations" in the top search bar and select the "Jump to donations" link.
3. Answer "Yes" to "Did you make any donations to charity?".
4. Follow the prompts. When asked for the amount, enter the total for the months hosted (e.g., $250 for 5 months) as a cash contribution.
5. Enter the name of the sponsoring non-profit organization.

IRS Eligibility Requirements

• The student must live in your home under a written agreement with a qualified 501(c)(3) non-profit organization.
• The student must be in the 12th grade or lower.
• You cannot receive any money, stipends, or reimbursements for hosting.
• The student cannot be your relative or a legal dependent. 

Important Filing Note:

The IRS requires specific documentation for this deduction, including a copy of your written agreement with the sponsoring organization and a summary of expenses. Because these must be attached, you may be required to print and mail your return rather than e-filing.