To be eligible apply for JEE Advance Entrance Exam, You need to qualify JEE Main Entrance Exam first. JEE Main is the gateway for the admission to various B.Tech/B.E. programmes offered by 31 NITs, 23 IIITs and 23 CFTIs and JEE Advance is for the admission to Indian Institute of Technology ( IITs). As per the eligibility to apply for the Exam you should be passed or appearing class 10+2. In order to get IITs, NITs, IIITs, GFTIs, You should have minimum 75% in 10+2 as a General category & 65% as a reserved category or you should be in top 20 percentile in class 12th from the respective board.

As you told that you are in class 11th but to apply for the exam you should be appearing or passed class 12th. You can check the further eligibility you can go through with the given below link.

https://engineering.careers360.com/exams/jee-main

Good Luck!

Of course she can clear JEE Advance provided she studies well in 11th and 12th standard. 

To eligible to give JEE Advance a candidate must first clear JEE Mains after which he/she can give JEE Advance. 

If you still have any queries feel free to ask in the comment section down below .